Learn how to determine when you got pregnant using these easy steps to find out when you conceived.
When Did I Get Pregnant?
Are you wondering, “When did I get pregnant?”? For some women, figuring out when they got pregnant is a must. They either want to know just for the sake of knowing, they want a different way to estimate a due date, or they want to determine who the father of their baby might be.
No matter what the reason, figuring out the possible date you may have gotten pregnant isn’t too difficult, but it is very important to note that it is just an estimation based on dates on a calendar. Unless you had a very tiny camera inside of you that could capture the exact moment the egg and sperm met, or you had medical help conceiving, there’s no real way (that I know of) to know your exact conception date.
Please note: I am not a medical professional. I am just a mom who has had four kids and has done research. Please seek the advice of a medical professional if you are pregnant and have questions. This is just to help you figure out an estimation.
Why am I writing this? I am asked online multiple times a day either at HubPages where I am a writer or on YouTube where I have created videos to help women figure out when they may have conceived. Hopefully this helps!
Also note that this post contains affiliate links. Thank you!
For a very in-depth reading on finding out when you became pregnant, read this very informative article (written by me!). If you just want the step-by-step instructions, continue below.
When Was My Last Period?
Are you pregnant? Here’s where to start. (Not sure? If you have missed your period, it’s time to take a test!)
Step one:
(See video below for visual example)
Figure out when your last menstrual period (LMP) was. The date you want is the very first day your period started.
I hope you have been tracking your cycles! If so, open up your period tracking app or check your calendar. Find the date of your last period.
If you’re lucky, the app can give you an idea of your estimated conception date.
This part may be tricky for some women who:
- just had a baby and haven’t returned to their cycles yet.
- don’t have regular periods.
- have been on a birth control method and don’t always have periods.
If you fall into any of the three categories above, you may need to speak with a doctor about an ultrasound for a better estimation of your dates. Once you get your estimated due date, you can also figure out your possible conception date by plugging in your estimated due date into a pregnancy calculator/calendar. It’ll then give you all of your other estimated dates.
TIP: Most women conceive within 10-14 days after their last period. Ten days after your period is considered your fertility window, when you are most likely to ovulate. In pregnancy, this is considered the second week of pregnancy. If you don’t know when your last period was, you can count back 38 weeks from your estimated due date to estimate when your possible fertility window was.
Step two:
Mark your the first day of your LMP on a calendar.
Step three:
Use a pregnancy calculator to figure out your fertility window and estimated conception date. Mark these dates on a calendar.
I like to use the American Pregnancy Association pregnancy calculator to do this step. It’s super easy to use. You can use any pregnancy calculator you prefer. Note that they may slightly differ in dates and estimations given.
Now you have your estimated conception date! It is possible that the sperm met the egg within a day or so of this date if you have regular cycles.
Why is it only estimated? READ THIS
Something to remember: the day you have intercourse is usually not the day you actually conceive. It all depends on when the egg is released during ovulation, when the sperm meet the egg, etc. (All details on that can be found here.)
Who is the Father of My Baby?
If you were with more than one man during your cycle, you have one more step to complete.
Step four:
Once you have your dates from steps one-three above, you need to add a few more dates, namely when you had intercourse. Add the names of the men you were with, or just use Man 1, Man 2, etc.
Some things to remember:
- Only a paternity test will give you a definite answer in any scenario.
- If any of the men fall within your estimated fertility window, they could be the father since sperm can last between 3-5 days, sometimes longer.
- If you were with a man BEFORE your LMP, it is least likely that he is the father.
- Even if you were with a man before or after your fertility window, he might still be the father because it depends on whether your egg was released early, on time, or late.
Take at look at when each event occurred. In a perfect world, the man you were with closest to your estimated ovulation/conception date would be the father, but it isn’t always that simple.
Basically, whomever you were with in between your last period and your next expected period has potential to be the father.
Here is a video with actual examples for you:
You need to remember that all of these dates related to your cycle are just estimates, so please speak with your doctor if you need a more definite answer.
Have Any Questions?
Have any questions? Did I leave anything out? Leave a comment below!
READ NEXT: How Soon Can I Take a Pregnancy Test
Rosie says
It is more complicated than I realized – good information!
Karen Jaras says
This is very complicated. I am glad my kids are all grown and have kids of their own. The good old days when all my kids have the same dad.
Linda Manns Linneman says
This is some great information. In this world of ours today with all the testing and knowledge, it is alot easier. Thank you so much for sharing this great article
ellen beck says
I figured there would be ‘an app for that’ ha! I think it is a bit complicated at times to know the exact conception date. Mine are grown now, ad I always had a really good idea.
Lauryn R says
Very interesting post! I have three kids and have never really thought about the exact date they were conceived! This would be pretty fun to find out, thanks for sharing!
Sandra Caballero says
Very interesting and informative read.
Shah says
I broke up with my bf last year. We both started dating others but would also hook up with each other quite a lot too. I’m now pregnant, due 9th June. I was having very irregular periods so my due date changed by 2 weeks according to ultrasound. Conception date is approx 16th September (as google says)
I had sex with a guy on 4th September and used a condom. I then had sex with my ex on 11th & 12th September with no protection. It seems highly likely that my ex is the father but I need some reassurance here? I’m really starting to freak out now its getting closer to the baby’s arrival.
Marissa says
I’m sorry, but a paternity test is most likely your best option.
bre says
ok so basically my period was from june 23-27 i had almost kinda did something with this guy name desmond it like barely happened then i had sex with a guy july 3rd going into 4th which is now boyfriend and i know he ejaculated for sure i took a pregnancy test july 14th and it was negative then took one july 21st said im pregnant im due march 30th and now i guess i feel like i dont know who the father is like im scared kinda
Marissa says
Hi Bre,
Because it seems like these encounters happened around the same time, a paternity test is going to give you the most accurate answer. Keep in mind that even a ‘barely happened’ event can still cause pregnancy. I wish you all the best.