How do you know the exact date you got pregnant

Marissa is the writer of "ThePracticalMommy" and owner of Mommy Knows What's Best. She's a former teacher and a stay-at-home mom to four.

When did I conceive?

When did I conceive?

Want to Know the Exact Day You Got Pregnant?

Many women, upon finding out that they are pregnant, try to figure out the exact day the pregnancy began. This happens for several reasons: curiosity, due date estimation, or paternity issues.

No matter what the reason, finding out the exact day that pregnancy began can be tricky. Here's how to find out around what day you conceived by:

  • Understanding your menstrual cycle.
  • Calculating the date of ovulation.
  • Figuring out the date of conception.

When Did I Conceive or Get Pregnant?

The best way to calculate the day you likely conceived is to figure out approximately when you ovulated. According to Dr. Jennifer Landa, a board-certified OB/GYN, "If you have a "perfect" 28-day cycle, then ovulation happens on day 14 and you can get pregnant for about 12-24 hours after ovulation. Of course, many women don't have a 28-day cycle. Anything from 21 days to 35 days is considered normal. So to figure out when you got pregnant if you have a different cycle, ovulation comes 10 to 14 days before your period." If you had sex during this fertile window, then it is possible that you conceived during those days.

How Do I Figure Out When I Ovulate?

Ovulation is the time when you can conceive, so it is important to figure out what days you ovulate. Ovulation usually occurs in the middle of a woman's monthly cycle. For most, it occurs 10-14 days before your next period. You will need to subtract 10-14 by the length of your cycle.

Example of Figuring Out When You Got Pregnant

Let's say you had a period starting on February 1st, and you have a 28-day cycle.

  1. Mark the first day of your period (February 1) on the calendar.
  2. Then mark the last day of your cycle. If your period starts on February 1, and you have a 28-day cycle, then you would mark February 28th as your last day.
  3. Count back 10-14 days from February 28, which would be around February 14th-18th. Highlight these days. These are your most fertile days, so the days you most likely conceived would be around the 14th of February to about the 18th.

Conception calendar

Conception calendar

How to Figure Out the Conception Date

Let's say you ovulate on day 10 of your cycle. The egg comes out of the ovaries and waits for 24 hours in your fallopian tube. There are two possibilities of what could occur:

  1. Sperm from intercourse 3-5 days ago can meet the egg in the fallopian tube and fertilize the egg.
  2. Sperm from intercourse that day or the day after can meet the egg in the fallopian tube and fertilize the egg.

If you have intercourse during day 7 of your cycle and you ovulate on day 10, it's possible that conception can begin on day 10 or 11, depending on how quickly the sperm finds the egg. If you have intercourse on day 10 of your cycle, the same day you ovulate, conception can begin that day or the 11th day.

Example

Let's say you have a period on June 28th. On a 28-day cycle, your next period would be on July 26. 10 to 14 days before July 26 would be around July 12th to July 16th, which is when you'd be most fertile and more likely to conceive.

Note: These examples are based on a 28-day cycle. If you have a longer or shorter cycle, you should calculate your ovulation by subtracting 10-14 from the number of days in your cycle or by using this ovulation chart. On average, many women ovulate around these days. Those with irregular periods or who do not ovulate all of the time may not be able to rely on this method.

When Does Conception Occur?

The exact moment of conception is debatable, but it begins when a sperm burrows into the egg within 24 hours after ovulation. Some say conception is right at the moment when sperm meets egg; others say it's when the combination of sperm and egg implant into the uterus.

Scroll to Continue

Read More From Wehavekids

Symptoms During Ovulation

There are, of course, other ways to figure out ovulation, including signs of bodily change that occur during this time.

  • Changes in cervical fluid: Your cervical mucus will be clear and stretchy, like egg white.
  • Change in basal body temperature: After you ovulate, you will see a rise in temperature. You need to track your BBT over several months in order to predict when ovulation occurs.
  • Change in texture and position of the cervix: During ovulation, the cervix is open and becomes softer, and is positioned higher up.
  • Mild cramping: Some women report feeling a twinge on one side of their lower abdomen. This is known as mittelschmerz, and it should only last a few hours, if at all.
  • Light spotting: This is rare, but some women may experience light spotting when they wipe. Bleeding should not be heavy, red, or last more than a few hours.
  • Mild bloating: A rise in oestrogen levels prior to ovulation will trigger the release of LH (luteinizing hormone). This surge in hormones causes water retention, which leads to feelings of bloat.

How Many Days Before and After Ovulation Can You Get Pregnant?

The sperm survives in the female reproductive tract for six days, and the egg is viable for 12 to 24 hours after ovulation. This means you can get pregnant from having sex six days before ovulation and one day after. However, for best results, Dr. Sinem Karipcin, an OB/GYN and infertility specialist, says, "The best days to conceive are the three days prior to ovulation and the actual day of ovulation."

Calculating the day of conception is so complex!

Calculating the day of conception is so complex!

How Long Do Sperm Live?

Sperm can live for up to five days inside of a woman's body after intercourse. In some rare cases, and with perfect conditions, some sperm may even live up to seven days after intercourse!

Strong, healthy sperm can reach a woman's fallopian tubes in as little as 30 minutes, while it may take others several days. If an egg is there within 30 minutes, conception can occur right then. If the egg is not there yet, the sperm can live a few days in the fallopian tubes and fertilize the egg once it is released.

Can You Get Pregnant Right Before Your Period?

This is a very rare occurrence, but it can happen if a woman has a very short luteal phase (the 12 to 16 day period between ovulation and the onset of a menstrual period). In cases when a woman gets pregnant a few days before her period, ovulation occurred shortly before the start of a woman's period, meaning the luteal phase was only a few days long. Short luteal phases often result in pregnancy complications and miscarriages, so be sure to speak with a doctor. Progesterone supplementation can save future pregnancies.

I Highly Recommend This Ovulation Predictor Kit

Are Conception Dates Accurate?

Unless you have taken some sort of hormone test to determine the possibility of ovulation, there's no real way of knowing when you would exactly conceive. This is why women with regular cycles use the estimation of ovulation happening within the 10th-14th days of their cycle. The methods above are accurate within one to five days, but the exact date is impossible to pinpoint. This is why doctors use the date of your last menstrual period to date a pregnancy. They do this for consistency, and if you really want to know when you conceived, then you can assume it was about two weeks after your last period.

Tracking Your Menstrual Cycle

An average menstrual cycle usually lasts anywhere from 26-35 days in length. During this time, a few things occur:

  • Days 1-7: You will have a period. This is when the uterine lining is shed if there is no pregnancy.
  • Days 10-14: This is your fertile period, or ovulation, when an egg is released from the ovaries. This will likely be the time when you conceive.
  • Days 15-35: If you get pregnant, this is when implantation occurs. This stage is also known as the luteal phase.

This is an average cycle for many women. For those with irregular cycles, calculating your ovulation period can be tricky, and there is no real way of predicting when ovulation occurs without some type of hormone testing, which can be done with an over-the-counter ovulation predictor kit or blood test.

How Did I Get Pregnant?

When Does Implantation Occur After Ovulation?

Once sperm and egg have met and the egg is fertilized, the egg becomes a tiny ball of cells and travels down into the uterus. If it is a viable pregnancy, meaning that the ball of cells is growing normally, it will try to implant or burrow into the lining of the uterus where it can grow into a baby.

This process of implantation can happen about 7-10 days after ovulation, more or less. If you ovulate on day 10 of your cycle, implantation could occur anywhere from days 17-20 of your cycle. Basically, it happens about a week before your next expected period.

Most women do not realize that implantation has occurred, but some women do experience some symptoms:

  • Implantation bleeding or spotting that is brownish, pinkish, or reddish and is lighter than that of period bleeding. It should also only last a few days. If implantation bleeding lasts for longer than three days, then you may have a health-related issue, such as an ectopic pregnancy.
  • Slight cramping that is intermittent and lasts for less than three days. Some women may confuse implantation cramping for PMS cramping.

Once implantation has occurred, the embryo continues to grow and develop. This triggers a hormonal response from the body, which tells the body not to shed the uterine lining in the period. The hormone responsible for this is human chorionic gonadotropin (or hCG). It is the same hormone that is used by home pregnancy tests to indicate a pregnancy.

How Do I Calculate My Due Date?

On average, a baby arrives 240 days (40 weeks) after the first day of your last menstrual period. This is the gestational age, and it is what most doctors and health care professionals use to calculate the due date. It includes the two weeks prior to conception when a woman is not pregnant. Of course, this is based on a 28-day cycle, and days will need to be adjusted for longer or shorter cycles. But, even with adjustments, less than 10 percent of women actually deliver on their calculated due dates, so giving birth two weeks before or after the estimated due date is normal.

How Do You Calculate Gestational Age?

Gestational age is measured in weeks. To figure out the gestational age, you take the first day of your last menstrual cycle and count how many weeks it has been up to the current date. Delivery will usually occur around the 38th or 40th week.

when-did-i-conceive-get-pregnant

Why Do They Use the Last Period to Date a Pregnancy?

It is nearly impossible to know the exact date of conception, so doctors start with the first day of the last known menstrual cycle. A baby's actual age is called the "fetal age," and this age is two weeks less than the gestational age because it doesn't include the two weeks prior to conception. Doctors like to use gestational age because it is easier to count from a woman's last period than to guess when a baby was conceived. A baby can be delivered and survive any time from the 22nd week of pregnancy to the 41st week. Of course, the further along the pregnancy is, the better chance the baby will have of surviving without medical intervention.

Example: If your last period was June 28th, your estimated due date is April 4th. Does that mean you conceived on the 28th? No. Conception most likely occurred two weeks after, during the days of July 8th-July 12th.

Very few women actually deliver on their due dates. The due date is an estimation of when the baby could come. The baby and your body actually decide when the time is right for the baby to be completed with development and to be delivered.

Question: If your due date is April 4th but you deliver on March 28th, does that change the conception date?

Answer: No. Your conception date basically remains the same. It just means that your baby was ready to enter the world a few days sooner than expected!

When Did I Conceive Based on an Ultrasound?

Within the first two months of pregnancy, a woman will have her first ultrasound scan. Most of the time this is done to determine the due date, but sometimes it is done just to make sure the pregnancy is progressing normally.

From the scan, doctors can determine an estimated due date and a possible conception date. These dates are based on the measurements of the baby and of the uterus and how they correspond to average measurements.

Sometimes, the dates given from this scan can be off by a few days. For instance, a woman may think she is about 12 weeks and 3 days pregnant with a due date of August 10th and a conception date of November 17th, but her scan says she is about 13 weeks pregnant with a due date of August 6th with a conception date of November 13th. Does it change anything? Not at all. It just means that the measurements from the scan correspond to someone who is 13 weeks pregnant, and the dates are estimated based on that.

Scans given early in pregnancy are known to be off a few days, but later in the pregnancy, the scans tend to be right on target. The only time a scan would indicate you were further along in pregnancy during late pregnancy is when the baby is larger than expected, either due to genes or macrosomia (a condition where the baby grows to be large, sometimes due to gestational diabetes).

Just like basing your due date from your last period is an estimate, an ultrasound scan gives fairly accurate estimates about when your baby is due and when he or she was conceived.

When Did I Get Pregnant?

Who Is the Father of My Baby?

If you have been with more than one man during your cycle, you may be wondering: "Who is the father of my baby?"

You can use your dates to try to figure it out, of course, but your best chance at knowing without a doubt who the father is would be to have a paternity test done once the baby is born.

If you would like to try to figure it out and you have regular cycles, here's how:

  1. Using a calendar, mark your last period on the calendar and figure out your possible dates of ovulation (use the information above). Mark your possible days of ovulation with an 'O'.
  2. Think of each time you were with someone. Using #1 and #2 (and so on), mark each encounter on your calendar.
  3. Do any of the times fall within your ovulation dates?

Once you have your calendar marked, it's time to analyze. Start with the first man. Were you with him any time leading up to ovulation or during ovulation? If so, he could be the father. Same thing with the second man, and so on.

Look at the Following Scenarios and See If Any Apply to You

Scenario 1: You were with Guy #1 on June 20th. You got your period around June 28th. You then were with Guy #2 from July 1st-3rd and July 11th-13th.

Who is the father? Guy #2 would be the father since you had a period after Guy #1. Also, you were with Guy #2 during your fertile time.

Scenario 2: You have your period on June 28th. You were with Guy #1 on June 29th, July 3rd, and July 5th. You were with Guy #2 on July 7th-11th.

Who is the father? Guy #2 is most likely the father since you were with him closest to your fertile time. If for some reason, however, you ovulated sooner than the 10th of July, there's potential that Guy #2 could be the father since his sperm may have lived from the 5th-10th. In this case, I suggest a paternity test so there aren't any doubts.

Scenario 3: You have your period on June 28th. You were with Guy # 1 on the 10th of July, and you were with Guy #2 on the 12th of July.

Who is the father? There's no way to know without a paternity test. Since you were with both men so close together, it's possible that both of their sperm was in you when you ovulated and either one could be the father.

Again, a paternity test would be the sure way of knowing who the father of your baby could be. Once the baby is born, the test can be done and no one will have second guesses.

Paternity Test While Pregnant

While it is possible to determine paternity during pregnancy, the tests aren't recommended for basic cases. Why? Prenatal paternity tests can be invasive tests, meaning that a needle needs to be placed into the mother's abdomen and into the space where the baby is growing.

Paternity can be determined using amniocentesis where amniotic fluid is drawn through a needle, or chorionic villi sampling where tiny pieces of the chorionic villi found on the lining of the uterus are removed using a thin tube or a needle. Both carry slight possibilities of miscarriage, which is why they are not recommended for paternity testing alone.

There is a method to try to find the DNA of the baby in the mother's bloodstream during pregnancy, but this method is not 100% reliable.

For more information, visit the American Pregnancy Association website.

Date of Conception

Your date of conception, or the date of when you became pregnant, is an estimated date that can be figured out using the date of your last period. By knowing more about ovulation, conception, and implantation, it's easy to see how the date of conception is an estimated date since it's nearly impossible to pinpoint any of the three times in your cycle.

Even though it's an estimated date, knowing when you may have conceived can help with figuring out due dates and other pregnancy-related issues.

Best wishes on your pregnancy!

Disclaimer

I am not a medical expert and can only give educated answers to any questions you have based on my personal experience. Please seek proper advice and treatment from your doctor.

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

Questions & Answers

Question: I am 12 weeks pregnant. When did I get pregnant?

Answer: Without knowing when your last period was, I can't guess when you got pregnant. If you count back about ten weeks, that's around the time when you may have conceived.

Question: I am 11 weeks pregnant. When did I get pregnant?

Answer: Conception usually occurs around 10 to 14 days after your last period. If you count back nine weeks from now, it may have been around that time.

Question: If I’m due Sept 14, 2018, when did I conceive and when were the possible dates to have had sex?

Answer: You may have conceived around 38 weeks ago during your fertility window. It's usually 10-14 days after your last period.

Question: If i'm due October 6, 2018, when did I conceive and when were the possible days to have had sex?

Answer: Most women conceive 10 to 14 days after the last period. If you count 38 weeks back from your due date, you may have conceived around that time.

Question: If I’m 18 weeks and 5 days pregnant when did I conceive?

Answer: You may have conceived around 16-17 weeks ago.

Question: My last menstrual period was April 28. I was with guy number #1 on May 6th, then guy #2 I was with from May 11-14. When did I get pregnant?

Answer: Based on your last period, your fertility window may have been between May 8th through May 18th. If you ovulated earlier in your cycle, it is possible that it could be guy number one. If you ovulated in the middle of your cycle it could be guy number 2. Without knowing exactly when you ovulated, there's no way for me to make an accurate guess.

Question: I had unprotected sex on August 5th with guy #1. I’m pretty sure I got my period after but I don’t recall. I had unprotected sex again a few times around August 10-15th with guy #2. Who could the father be?

Answer: Without knowing when your last period actually was, there's no way to guess who the father is.

Question: My LMP was on February 20th. I had sex with my hubby on March 3rd. When will I get pregnant?

Answer: Based on your LMP, you had sex during your fertility window, which is a good thing. Since you're not expecting your period for a few more days, I suggest waiting until you miss your period before taking a test.

Question: I am three weeks pregnant, when did I get pregnant?

Answer: Most women conceive about ten to fourteen days after their last period. Most also don't find out they are pregnant until they are four or five weeks along.

Question: My last period was on the 3rd March 2018. I had sex on the 17th, and my cycle is 31 days. When will I ovulate and when can I get pregnant?

Answer: Based on your last period, your fertility window may be between 3/16 and 3/26. If you have sex between these dates, you can get pregnant.

Question: My period came on 1/5/17 and then again on 2/7/18. I had sex with guy #1 on 1/21, and he did fully ejaculate in me. I had sex with guy #2 on 1/25, and he pulled out but stated he might have pre came inside of me. Who’s the father?

Answer: If you got your period in February, then you would not be pregnant.

Question: Why do I get symptoms as though my period is coming and don't get it? I took the morning after pill a month ago. Is the pill affecting my period now?

Answer: Yes, the morning after pill can mess with your cycles and hormones. It might be a month or two before you're regular again.

Question: Hi I am 14 weeks pregnant. I'm due 20th November. I had sex with a guy on the 6th February. I was bleeding around the 14th February. Not as heavy as my normal period but still bled and had pains. I got back with my partner around 16th. Who is the father? Going by the due date and the week 14 weeks which they go by the first day of my last period. It would make it my partners?

Answer: Based on your last period and your due date, the father would be whoever you were with after your period.

Question: I am a month pregnant. When did I get pregnant?

Answer: Conception usually occurs 10-14 days after a period.

Question: My due date is on October 6th. When did I conceive?

Answer: Count back 38 weeks from your due date. Conception may have occurred around that time.

Question: She had period 26 and stopped 29th the same month. On the 5th of June she had unprotected sex. Is it possible that she is pregnant?

Answer: Anytime you have sex you can become pregnant. While it's early in her cycle, is not uncommon to become pregnant then. She will have to wait until she misses her next period to find out.

Question: I had sex with my wife between 27th and 30th of December and she told me that she was ovulating. On 24th of January, we went for a scan and the doctor told me she is 5 weeks pregnant. Please am I the father of the child?

Answer: Pregnancy is counted from the first day of the last period, which should have been around 10 to 14 days before ovulation. I think you should read up on how pregnancy occurs, and speak with your wife.

Question: If I'm due the 9th of June 2018. When did I likely conceive? Which dates possibly?

Answer: Conception usually occurs around 10 to 14 days after your last period, during the time of ovulation. If you count back about 38 weeks from your due date, that is around the time when you may have conceived.

Question: I had sex the day before I ovulated. 12 days later I spotted a pinkish brownish color that lasted a couple of hours, and now I’m eight days late for my period. Could I be pregnant?

Answer: The only way to know is to take a test.

Question: My LMP was April 28. I had sex on the 13th with guy 1 and guy 2 on the 16th. My period was due May 23. When did I get pregnant?

Answer: Based on your last period, your fertility window may have been between May 8th and May 18th. Being that you were with both men within a few days of each other, I cannot make an accurate guess.

Question: My girlfriend is pregnant, and her due date is December 26th, 2018. We had sex daily from April 2nd until May 26th. It's possible that she was with someone else from March 26th until April 2nd, which is before she and I got together. Who is most likely the father?

Answer: Without knowing when her last period was, I can't really give you an accurate guess. That being said, when I was pregnant with my girls, they both had due dates right in the beginning of January, and I conceived in mid to late March. Please keep in mind that I am not a medical professional. You should encourage your girlfriend to speak to her doctor about these things.

Question: I found out I was five weeks pregnant on November 22nd. When did I conceive?

Answer: Most women conceive around 10 to 14 days after their period. If you were five weeks pregnant on November 22nd, then you may have conceived three weeks before then.

Question: If I'm due to give birth June 7th, 2018, when did I conceive?

Answer: If you count back 38 weeks from June 7, that'll be around when you conceived. It is basically 10-14 days after your last period.

Question: My last period started on Jan 3rd. I had sex with guy #1 the 14th and guy #2 the 18th. Who could be the father?

Answer: Based on your last period, your fertility window may have been between the 13th and the 23rd. Being that you are with both men within just a few days of each other, I cannot make an accurate guess. I suggest a paternity test.

Question: My last period was on the 28th of March. I had sex on the 15th of April, and my cycle lasts 26 days. How many weeks pregnant am I?

Answer: You're about six weeks and one day pregnant. If you Google 'pregnancy calculator', you can plug in your information and get a calendar that tells you how far along you are.

Question: My last menstrual period was on the 29th of March 2018. I had sex with guy #1 on the 31st of March, and then I had sex with guy #2 on the 1st of April. I had sex with guy #1 again on the 2nd of April. When did I get pregnant?

Answer: Based on the date of your last period, your fertility window may have been between April 8th and April 18th. It is possible that either the encounters on the first or second of April could have caused your pregnancy.

Question: I was with Guy #2 on February 25th, and took Plan B on the 27th. I then got what I believe was my menstrual period on March 3rd, which lasted three days. I then was with guy #1 the entire month of March and April. On April 15th, I got a positive PT. From my LMP, it stated I was around seven weeks, but when I got an ultrasound done on April 30th, I was measured early and was seven weeks. Who is the father?

Answer: If you were only with Guy #1 in March and April, then he is most likely the father. It is possible the period you experienced in March was from the plan B, and not your actual menstrual cycle. That type of birth control can mess with your cycle for a few cycles. As I am not a medical professional, I highly suggest you speak with your doctor about a paternity test to confirm.

Question: The last time I had sex was Feb 9th. What will be my due date if I don't know my last menstrual period?

Answer: Your doctor will do an ultrasound and can give you a due date estimate based on the measurements from the ultrasound.

Question: My LMP was 4/20/18. I had sex with guy #1 5/3/18 and guy #2 5/4/18 very late technically 5/5/18. Who's the father?

Answer: Your fertility window may have been between April 30th and May 10th. Being that you were with both men only a day or so apart, there's no way to know without a paternity test.

Question: My period was on April 13th, 2017. I had sex with Guy #1 on April 14th, and then Guy #2 on April 19th. I was with Guy #3 on the April 28th. My due date was 18th Jan, but I gave birth on the 28th of December. Who could the father be?

Answer: When you give birth does not change when you conceived. Based on your last period, your fertility window may have been between April 23rd and May 3rd. I would guess that it could be either Guy #2 or Guy #3. Without knowing exactly when you ovulated, there's no way for me to make an accurate answer. I suggest a paternity test.

Question: My last period was December 20th 2017. I'm due September 22nd, 2018. Is there any way that I got pregnant on December 16th, 2017?

Answer: If your last period was on December 20th, then you most likely became pregnant around the 30th or so of December.

Question: Can I get pregnant 7 days after my period? My first period was January 6th and finished January 9th. I had sex January 16th.

Answer: Yes, you can get pregnant from sex 7 days after your period. It all depends when you ovulated.

Question: I slept with my ex-girlfriend on July 15th. In December, I was told that she's six months pregnant, and the baby was due on April 5th. Could I be the father?

Answer: Without knowing exactly when her last period was, I cannot give an accurate answer. However, I can say that there is potential that you could be the father if she was due at the beginning of April, and you were with her in July.

Question: My last period was Jan 11. Since then I have not menstruated and have taken six pregnancy tests with negative results. Is it possible I'm testing too early?

Answer: Periods can be delayed for other reasons. If you are pregnant you should have gotten a positive pregnancy test by now. I suggest speaking with your doctor.

Question: My LMP was March 11. I then had unprotected sex on March 25. I had very light bleeding from April 7-8. I've now missed my period, but I have light bleeding when I wipe. Could I be pregnant?

Answer: It's possible that you are pregnant.

Question: If I had sex with a girl on January 7th, and she is due on September 30th, could I be the father?

Answer: It depends on when her last period was. If her last period was near the end of December, it is possible, provided that she wasn't with anyone else around the same time.

Question: If I’m due February 24, 2019 when did I conceive & get pregnant?

Answer: If you count back 38 weeks from your due date, you may have conceived around then.

Question: My due date is June 26th. When did I conceive?

Answer: Most women conceive around ten to fourteen days after their last period. If you count back thirty-eight weeks from your due date, you may have conceived around then.

Question: My due date is on July 13. When did I conceive?

Answer: Without knowing when your last period was, I can't guess when you conceived. Most women conceive about 10 to 14 days after their last period. If you count back 38 weeks from your due date, you may have conceived around then.

Question: I am 4 weeks pregnant. When did I get pregnant?

Answer: You may have become pregnant around 2 weeks ago.

Question: My last menstrual period was on December 13th. I had sex with guy number one on the 11th of December and with guy number two on the 22nd and 23rd of December and on January 1st. My due date is September 19th, and all ultrasounds confirmed that the baby was measured for that due date until the last one measured the baby at 31 weeks, two weeks ahead of the due date. Does this mean that guy number one could be the father?

Answer: Guy number one is most likely not the father of your baby. Since you had your period after having sex with him, he is less likely to be the father. A baby's measurements do not determine when conception occurred.

Question: I am 5 weeks pregnant. When did I get pregnant?

Answer: Most women become pregnant in what is considered the 2nd week of pregnancy, which for you might be 3 weeks ago.

Question: Is it possible for a dated ultrasound to be four weeks off?

Answer: Unless there is a problem with the baby, ultrasounds usually are not that far off.

Question: I am 16 weeks pregnant. When did I get pregnant?

Answer: Most women conceive 10-14 days after their last period.

Question: My girlfriend and I had sex on December 17, 2017. She found out that she was pregnant in January 2018 and gave birth on September 21, 2018. Could I be the father?

Answer: Since I do not know when her last period was, I cannot give you an answer. This is a conversation you should be having with your girlfriend and not the Internet.

Question: My LMP Was March 5th. I had sex with Guy #1 on March 16th. I had sex with Guy #2 on March 20th. When did I get pregnant?

Answer: Your fertility window may have been between March 15th and March 25th. Being that you were with both men during that time, there is no way to make an accurate guess.

Question: I was with Guy #1 on March 21st and then had a period March 31st. Then I had sex with Guy #2 on April 10th. When did I get pregnant?

Answer: If your last period was March 31st, then you most likely conceived in April. As I'm not a medical professional, I suggest speaking with your doctor.

Question: I have a due date of Oct 9, 2018, when would I have conceived?

Answer: Conception usually occurs 10-14 days after your last period. If you count back 38 weeks from your due date, you may have conceived around then.

Question: My LMP was on February 4th. I had sex with guy #1 on the 12th, 13th, 14th, and 16th. Then I had sex with guy #2 on the 24th. When did I conceive?

Answer: Based on your LMP, your fertility window may have been between February 14-24. While I'd guess that guy #1 is more likely to be the father, I can't rule out guy #2 if for some reason you ovulated late in your cycle.

Question: My last menstrual period was the 23rd of January, and I had sex with my guy on the 28th of January. How many weeks am I'm pregnant?

Answer: You are around 8 weeks pregnant.

Gaby on August 22, 2020:

Guy #1 Had sex Jan 1

Took a pregnancy test Jan 15 negative

Jan 16 bleed not sure if it was implantion bleeding or period it lasted 5 days it was red and runny

Had sex again on Feb 3-4 with guy #2

Took a pregancy Feb 10 negative ( because i was scared about guy #1 )

On feb 18 i was suppose to get my period and i didnt took a pregnancy test feb 21 and it wad postivie my due date is oct 22 who is the dad

Cesilia Pedro on August 19, 2020:

I’m 35 weeks and 3 days and I want to know what day I got pregnant please help me

Marissa (author) from United States on August 01, 2020:

Donah, around 23 weeks ago.

Donah on July 29, 2020:

If am now25 weeks pregnant when did I concieve?

Anonymous on July 22, 2020:

I last slept with my bf on 15 March n on my periods. Date I saw clots it was on 26 March n on April I saw clots again n I slept with other guy on April s it possible for da guy to the father?

Sne on July 18, 2020:

My last periods were on the 19 of May 2020 i had sex with guy #1 on the 18 and on the 25/26. On the 27 i was on fertile window until i ovulate on the 31 then on the 1st on June about 22.00 i had sex with guy #2. Who can be the father?

Gbemisola on June 30, 2020:

My ovulation is around 24 and fertile window is 20_25 circle lenth is 28 I have sex on 23 will I be pregnant

Ezeh Gracious on June 28, 2020:

My last period was on June 1 and I had sex junes 20

Is it possible for me to get pregnant

Walter on June 12, 2020:

i had sex with my girlfriend on 31st July 2019 and she gave birth on 1st April 2020 but she never told me her last periods,do you think that child belongs to me according from the first day i had sex with her and the date she gave birth on.

Marissa (author) from United States on May 16, 2020:

38 weeks ago.

Cynthia on May 13, 2020:

Am 40 weeks pregnant when did I get pregnant?

Marissa (author) from United States on May 12, 2020:

Tori, you may have conceived around 28-29 weeks ago.

Tori on May 05, 2020:

Im 30 weeks and 7 days pregnant when sid i concive

princess on February 27, 2020:

i'm now 5months pregnant when i got my first ultrasound on november 26,2019 i am 6 weeks and 6 days pregnant ..i got sex with my present on october 16,17 and 18 then i got sex with other man on 20 .. who may be the father ?

queen love on January 22, 2020:

If i was 12 weeks on september 23rd 2019 when did i conceive?

Cathe on January 13, 2020:

Im 39 weeks pregnant,i think that i conceive from the 15 of april according to ultrasound,but checking on google that i conceive the 27,28,30. How is it possible

Migale on January 10, 2020:

My LMP was 10/20/2019. My ex has a vasectomy but slept with him in October. Guy #2 I slpet with November 1st I'm 11 weeks and 5 days. Who's likely the daddy? My due is July 26th 2020.

Lue lue bby on December 29, 2019:

i dont know the date i for pregnant my last period was 14 of August 2019 can u help me

Bobby love on November 27, 2019:

I am 13 weeks and 5 days today my Due date is May 29th 2020 when did I conceive

Kelo on November 22, 2019:

The 1st day of my last periods was on the 15 or 16 of September then i had sex with a guy1 on the 24th and i was with guy 2 on the 28th till 8 of October then took the clear blue on the 16th of oct indicated 2-3 weeks pregnant..when did i get pregnant?

Candice on November 20, 2019:

Can i ask i had sex with two guys i don't know the father my last period was 8 may 2019 i slept with the first guy on 12 may and i slept with the other one on 28 may who can be the father

Zee on November 03, 2019:

I had unprotected sex day before my last period with guy#1 on the 18th May n my periods were normal .on the 21 May i had unprotected sex with guy#2 so who could be the father of my baby?

Nicole on October 04, 2019:

The 1st day of my last cycle was Aug 22. It lasted until Aug 27. Aug 29 I had sex with guy #1. Aug 31 and Sept 9 I had sex with guy #2. My cycles are irregular. July my cycle was from July 25-29. Positive pregnancy test on Sept 28. Who is the father?

Jackie on October 03, 2019:

I took out my birth control Jan 15th. Hadn’t had a period in 3 years. Had some bleeding according to my period tracker feb 4-9 if I had sex feb 1-2ish one night stand. Had sex with guy #2 from feb 12-23. Got a negative test feb 28th but got a positive test March 3rd. Whose the father ?

Jullia on October 01, 2019:

Hey am 10 weeks nd 3 days pregnant last had my period during july slept with guy1 on the 20-21 and slept with guys 2 on the 27 july i need to know who is the father?

Leah on October 01, 2019:

The first day of my period was 19th August. I had sex on the 4th Sept and 14 Sept. Can it be possible that i am pregnant?

bukky anonymous on September 30, 2019:

i need help, i really dont track my cycle... but my period lasts 3-4 days, if i had sex with guy1 on 26 of july and had sex again with guy2 on the 8 of august, Although i saw my last period first day on the 18th of august, scan says i'm 7 weeks and 1 day on the 27th of september and also that am due on the 14 of may the following year(next year), who is the father?

Janet on September 30, 2019:

My due date is dec 30 2019 when was is most likley that i got pregnant

Lily on September 28, 2019:

On 8/25/19 my ultrasound said I was 5weeks Amy way I got pregnant on the 8th!? Do u suggest prenatal testing and accuracy? I’m a mess :(

Jan. on September 17, 2019:

I had sex w.guy 1 July 5th, had a period July 6th-11th and wasn't active again until July 20th w.guy number 2 and now i'm 10 weeks pregnant. I went to the E.R on July 26 but my urine sample was negative. guy #2 is the father?

Marissa (author) from United States on September 17, 2019:

J Henderson, yes.

Marissa (author) from United States on September 17, 2019:

Most women ovulate 10-14 days after their last period.

J Henderson 2k15 on September 10, 2019:

My last menstrual cycle was May 19th - 23rd. I had sex with Guy #1 May 25th & 26th & had sex with Guy #2 May 31st, June 1st, & June 2nd. Is it too close to tell who’s the father?

Annie Ping on September 08, 2019:

My last menstrual cycle was March 8th,2019. I have a 31 day cycle. It lasted from the 8th -13th. My next expected period was April 8th,2019. I took a pregnancy test on April 16th. I was 5 weeks. When could I have ovulated? I am 26 weeks and 2 days now

My name is jesica on July 12, 2019:

I had sex with guy1 April throughout the month,even days to my monthly cycle which came April 25 and lasted for 5days,i even had sex with him after my ovulation..and I also had sex with guy2 may 14..i did a pregnancy text and it shows am pregnant,but the problem is that I don't know the father of the unborn child..please I need answers,thanks

shantell on July 10, 2019:

I had sex on 29june and ovulute on 3july and my period is on 1july can I be preg?? Help m

Nia on June 28, 2019:

if my due date was oct 4 2016 can you tell me when my last period was based on my due date? and what day did i likely get pregnant on?

Sierra on June 25, 2019:

If my due date is August 26th 2019 when did I get pregnant

JJ on June 23, 2019:

My lmp was 2/14/19

Had sex with guy #1 feb 22 and 26

Had sex with guy #2 March 2nd

I am currently 18wks 2 days

I did a prenatal paternity test and it said guy#1 is 99.9% the father but I am always doubting until I see the baby. Can you give your opinion?

Mary on June 23, 2019:

My last period was 21 May when did I conceive

Marissa (author) from United States on June 17, 2019:

MG, any time you have sex there's a chance of pregnancy.

MG on June 13, 2019:

Hello I would like to ask a question I had sex on June 1 supposedly I ovulated on June 6 my period was May 23 is there a possibility of pregnancy

Marissa (author) from United States on May 29, 2019:

Daytona, pregnancy is measured from the first day of the last period. That includes the two weeks leading up to conception.

Daytona on May 27, 2019:

I have endometriosis, and my periods are so crazy and irregular that I have never really kept track of when they come or how often and what not. On May,13 I found out I am pregnant. I went to the doctor and had and ultrasound done the same day. From the ultrasound the Dr said it looks about 4 1/2 weeks. On April 13th I had intercourse for the first time in months. 2 to 3 days later I had intercourse again with a different man. Reading everything I have read on this website I am confused so is the 4 weeks including the 2 week preconception days or no? If yes, when did I convince if no,? Help me I'm confused and need the closest possible answer I can get. I continued to have intercourse with man #2 for bout a week after the initial day. After that week I continued to have sex with man #1 for a few weeks??????

Marissa (author) from United States on May 06, 2019:

Lindiwe, about 33 weeks ago.

Lindiwe on May 06, 2019:

I am 35 weaks pregnant when did i fall pregnant

Marissa (author) from United States on April 04, 2019:

Katie, since you don't mention your LMP, I can't give you an answer.

Marissa (author) from United States on April 04, 2019:

Unknown, most women conceive within 10 to 14 days of their last period.

katie on April 02, 2019:

I have been old by baby measuremnts i am 8 weeks pregnant today! Does this mean 8 weeks since conception or 6? my due date is the 13th november 2019 & i am asking as i had sex with my ex on the 14th feb due to drink and me and my partner having a massive falling out. My partner and I have regular sex other than this & we had sex again starting from the 17th feb. Please tell me the chance is mostly my partners as i hate what i did and wouldnt want a baby with anyone else or to break his heart

unknown on March 25, 2019:

I'm 5 weeks pregnant,my last period start on 11th February-16 February so when did i get pregnant

Jazmine on March 20, 2019:

When did I conceive?? I had my child on December 23rd was with one guy in the beginning of February the 2nd guy the end of February but he didn't come in me ... the 1st guy we never use any protection 2nd guy we did

Marissa (author) from United States on March 17, 2019:

if you had a. After the first guy, he is most likely not the father. As I am not a medical professional, I suggest you speak with your doctor.

GloveGirl on March 15, 2019:

Please Help Asap. Not to Be A pest Im just really freaking out Rn cant eat or sleep. I’m a mess.

Marissa (author) from United States on February 18, 2019:

Ashley, you may have gotten pregnant about 10-14 days after your last period.

Ashley on February 07, 2019:

My doctor said I was 2 weeks pregnant on Jan 21, 2019 what day did I get pregnant on?

Alliyah on February 05, 2019:

If I found out I was pregnant on January 28th when did I conceive ?

Prudance on February 01, 2019:

Had sex one night stand with the other guy on the 14 Dec and with my boyfriend on the Dec, last period was on the 29 Nov, can my boyfriend be the father? And we had sex again with my boyfriend on 7 Jan can the child be like him

Stacey on February 01, 2019:

I can't exactly figure out when my last period was due to not keeping track but yesterday i took the Clearblue test and it says 3+ weeks.

Any help please

BriBae on January 30, 2019:

My last period was Nov 3-8. I had sex with Guy 1 Nov 23, & Guy 2 Dec 11. I found out I was pregnant Dec 21. I am now 8 weeks. Who most likely is the father?

Jenee on January 30, 2019:

My lmp was june 4-8th. My due date is March 12th. I was with guy #1 May 27-30th. Then guy #2 June 8th. Then guy#1 june 9th- 20th. Who is the father?

Marissa (author) from United States on January 18, 2019:

Natasha, a due date is based on your last period, not when you had sex.

Londie on January 14, 2019:

Hi I had my last period on the 22 November 2018 then on the 11 of January 2019 I found out that Im 8weeks and 4days pregnant ........my question is Whan did I conceive because when Im counting back day by day till the last day of my period it not 8weeks 4days so please help me how to count

Sandra on January 12, 2019:

My last period was 24th of augt and i had sex 4th of September with another guy on 8th of same month. When did i get pregnant im 17 weeks now

Shuu on January 12, 2019:

My last period was on 21may 2018 I slept with a guy 1 from 24may until 7 June and the guy 2 on 9th June.. Now I'm 33 weeks 4 days pregnant who is likely to be a father?

Eliza on January 12, 2019:

My last period was on 5th Dec I had sex on 8th and9th with guy #1 then on 12th I had sex with guy #2 could guy #1 be the father

Natasha on January 03, 2019:

I only had sex on the 2 may 2018 when is my due date

Marissa (author) from United States on January 02, 2019:

donald, without knowing when her last period was, I can't make a guess. Most women conceive about 10-14 days after their period, which was about 36 weeks or so ago. It's just an estimate.

Marissa (author) from United States on January 02, 2019:

Ryan, the day you conceive is not always the day you had sex. It's the day that sperm meet the egg after ovulation. Sex could have been a few days before or right after ovulation.

on January 01, 2019:

I had sex with a girl from may /2 /2018 and again in may /19/2018. She's 38weeks pregnant now am I the father to the child? When did she conceived?

Ryan on December 30, 2018:

my lmp was around May 14th, I am currently 33 weeks and 3 days pregnant, me and my boyfriend had broke up around May 23rd I had sex with someone else may 24th BUT we used a condom, now my doctor says I conceived on May 24th is that the day I had sex?

Marissa (author) from United States on December 28, 2018:

Lynn, if you had a period after your one-night stand, chances are that he is not the father. As I am not a medical professional this is just a guess.

Marissa (author) from United States on December 28, 2018:

Dace, it's possible that the first guy could be the father, but the only way to know for sure so take a paternity test. As I am not a medical professional, this is only a guess.

Marissa (author) from United States on December 28, 2018:

Farra, most women conceive 10 to 14 days after the last period.

Lynn on December 28, 2018:

I'm freaking out! I had my period in 10/13-10/16 and was having sex with my bf from 10/16-10/30, we broke up that day. And I had sex with this other guy on 11/5, I didn't realize he didn't use a condom till it was too late, he pulled out and in about 12 hours after I took a Plan B. I got back together with my bf and had sex with him from 11/12-11/22. I was spotting on 11/18, bled very heavy 11/19-11/20 and was spotting from 11/21-11/23. I haven't had my period since. I had a transvaginal ultrasound on 12/13 and there was nothing. Last night, 12/27 I had 3 positive pregnancy tests. Is it possible that the baby is the other guy's? I never have one night stands but then the 1 time I do I end up pregnant!!

Dace on December 25, 2018:

My last period was 4th October 2018 and I had sex with guy #1 immediately after my period ended for days on days . Then I had sex with guy #2 on the 26th oct. who is the possibles dad?

Farra Zack on December 20, 2018:

My period used to be regular lasting 5-7days. Then I had my LMP on Sept 3rd, only for 3days. Supposedly my next period on Oct 7th but it didn't come out until I found that I'm pregnant on 6th November. Based on ultrasound, my EDD will be July 15th. When did I conceived? Is there any possibility ovulation on October?

Sara on December 13, 2018:

Hi I had unprotected sex 3-5 days before my period last month at least I thought it was my period it was a week early...this month I'm not due for my period for another week but two days ago I started spotting on and off and discharging small brownish stringy mucus and it continued on till he next day and today I haven't spotted but I'm lightly cramping an having light lower backpains what's going on I had my tubes tied over 9 yrs ago?

Nicole on December 12, 2018:

I’m due feb 20th not sure of my last period date but my husband thinks we conceived in April would that be possible? I think it’s likely to be end of May/June

Marissa (author) from United States on December 11, 2018:

Carabear, pregnancy is measured from the first day of your last., Not from conception.

Marissa (author) from United States on December 11, 2018:

Bucy, conception usually occurs about 10 to 14 days after the last period.

Marissa (author) from United States on December 11, 2018:

Jenny, without knowing when your last period was, I cannot make a guess.

Carabear83 on December 03, 2018:

I need help. I found out November 11th i was pregnant. The first day of my last period was October 10th and i always have regular periods lasting 3-4 days. When i went to the doctor and they went by my LMP my due date was July 17. I went and had a ultrasound done today and they told me I was 8 weeks 2 days, due date July 13th and they said my conceived date was around October 20th-21st. By my calculations that isnt 8 weeks, its 6 weeks. Why isnt it adding up? I really need to know my conceived date to figure out who the father is. Thanks

Bucy on December 03, 2018:

I'm 5 weeks 1 day when did I get pregnant

TomekiaHall on November 30, 2018:

Hello if my due date is june 29,2018 when did I get pregnant

Jenny Gellecanao on November 29, 2018:

Hi I need help, Im 10 weeks and 4 days pregnant. I have sex with my boyfriend in august 28 and the man I've known from a bar on September 11, I really don't know when my last period. I want to know who is the father of my baby. Thank you

Marissa (author) from United States on November 28, 2018:

Jed, by the time you were with the other man, it seems that you may have already been pregnant by your boyfriend. I still suggest a paternity test.

Jed on November 25, 2018:

Had my Lmp on 26th july, i used herbal cleanser from 3rd to 10th aug while sleeping with my boyfriend, the rest of the days i was also sleeping with him somedays we skip but on 20th aug i slept with another guy, on 21st i had tender breasts and on 26th took a test and it was positive, on 14th sept had an ultrasound and i was 6wks 5days pregnant who might be the father of my baby? Pls help

Marissa (author) from United States on November 23, 2018:

Lee, unfortunately, because you took the plan b pill, I cannot make an accurate guess. It often changes your hormones and your cycles.

Lee on November 19, 2018:

I need help if you can my last period was 6/25 i had sex on 7/2 with guy #1 and the condom broke i took the plan B pill on 7/3 and had sex with the guy i was seeing again on 7/4 without protection and i started bleeding again on 7/7 i had sex with guy 2 again on 7/13, and 7/23 without protection im due april 1st how do i know if it was guy 1 or 2

Sanhee on November 11, 2018:

I had my period on 19 October to 22 October and i had sex on the 25th is possible for me to be pregnant and how far I'm?i can feel my body is changed and my cravings

Marissa (author) from United States on November 09, 2018:

Jillian, I'm not sure what you mean by safe period. If you are interested in tracking your cycles, I suggest using an app.

Marissa (author) from United States on November 09, 2018:

Ella, being that you were with both men within just a few days, there's no way for me to guess.

Ella on November 07, 2018:

My LMP is feb 15. I slept with guy #1 feb 25 then he used withdrawal. I slept to a guy #2 feb 27,28 till march and he cum inside me since we started having sex. My due date is on november 22. I just want to know who the father is and when did i conceived. Thanks a lot.

Jillian morris on November 04, 2018:

I saw my menses last month on the 7 of october ,and this montg i have seen my period on the fifth meaning i have a 30 cycle but i dont know hiw to calculate my safe period

Ella on November 04, 2018:

My LMP was around feb 15. My due date is on Nov 22. I slept with a guy #1 feb 25 using withdrawal. Then i slept to a guy #2 feb 27,28 march 1 & 2 without using any contraceptives. Do you think who is the father of the baby? Thanks so much.

Marissa (author) from United States on November 03, 2018:

Faith, most women conceive 10-14 days after their last period.

Marissa (author) from United States on November 03, 2018:

Savannah, without knowing when your last period was, I cannot make a guess. I highly suggest you speak to a doctor.

Marissa (author) from United States on November 03, 2018:

Febwoman, without knowing when your last actual period was, I cannot make a guess.

Marissa (author) from United States on November 03, 2018:

Lurdes, if you had a period after the first man, he is not likely to be the father. As I am not a medical professional, you must seek the advice of a doctor to get the actual answer.

Marissa (author) from United States on November 03, 2018:

faith, based on the information you provided, my guess would be it is possibly the second person. As I'm not a medical professional, you must seek the advice of a doctor to get the actual answer.

Can you tell the exact date you got pregnant?

Knowing the exact day of conception is a difficult thing. Sperm can live in a woman's body for up to five days, making it impossible to calculate exactly when conception occurred. It is not a fine science. In addition, women ovulate anywhere from 11 to 21 days after the first day of their last period.

How do you know what day you became pregnant?

The best way to determine your conception date is with a pregnancy confirmation ultrasound. A pregnancy confirmation ultrasound can help you determine approximately when you conceived and the age of your growing baby.

Is the day I conceived the day I got pregnant?

Sperm can live for up to five days inside your fallopian tubes. So, it could be up to five days after you have sex that you release an egg (ovulate) and it gets fertilized by a waiting sperm. That's the day you conceive.