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Pregnancy Conception Calculator: Discover When Your Baby Was Conceived

You can use a pregnancy conception calculator to determine when your baby was conceived. In order to find out your pregnancy conception date you need to know the date of your last menstrual period, the average length of your menstrual cycle and the average length of your luteal phase.

Knowing the length of your luteal phase is very important to accurately determine the conception date.

If you have not been charting your fertility and do not know this number, you can just use the average 14 days value, which is based on the fact that ovulation technically is most likely to occur 14 days before your period is due, unless of course you get pregnant.

If you have a 28-day menstrual cycle and your luteal phase is of approximately 14 days in length, you probably ovulated around day 14 of your cycle and that is the time when your baby was probably conceived. This is important also when deciding when to take an early pregnancy test.

Not all women have a text book menstrual cycle like this. In fact, most women tend to ovulate between day 13 and 16 or even later depending on how regular their cycle is. For example if your cycle is 45 days long, you ovulate around day 20, which is close to the conception date of your pregnancy.

The luteal phase can also vary in length depending on each individual woman. In average it is from 9 to 16 days long. This value should be calculated by using the average value of your previously charted fertility cycles. It you have not been doing so, you can use the average value of 14. 

Using The Pregnancy Conception Calculator Below

This pregnancy conception calculator allows you to determine your conception date as accurately as you possibly can based on your unique data. It is simply the same type of calculation used to determine your pregnancy due date. Have fun using this free online pregnancy conception calculator! 


This pregnancy conception calculator is very easy to use. 

Just enter the required information about
 your menstrual cycle

and submit to find the answer.


Enter The Date of Your Last Menstrual Period:  
(MM/DD/YYYY)

Enter Your Average Length of Cycles:  

Enter The Average Luteal Phase Length:  






Your Baby Was Most Likely Conceived on This Date:


Pregnancy Conception Date:

Your Conception Date

Your conception date is just an approximation. Many women think that their conception day corresponds with the day they had intercourse. This is not correct because sperm can live for 3 to 5 days within a woman's reproductive tract as long as she has fertile mucus.

This means that technically, fertilization can occur even if intercourse happened several days before the egg is released.

That's why knowing when you had intercourse is not the appropriate date to use when determining your conception date.

Determining Your Baby's Age of Development

By using this pregnancy conception calculator, you can learn more about your baby's developmental stage in utero and when he or she is do to be born.

Based on the inforemation you have entered above, here is more information about your baby:

Your baby is: old.

Your baby is expected to arrive on:

Congratulations, your baby is safely developing in your uterus!

Now is the time to think about your best prenatal care.
During your pregnancy you should eat healthy foods, avoid alcohol, give up smoking, and rest as much as possible.

Natural pregnancy care is the best way to stay healthy during pregnancy and prevent minor pregnancy discomforts.

Many Blessings!




Fairhaven Health Fertility



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