Conception Calendar Pregnancy. Calculate your due date based on when you conceived or the first day of your last period. Our conception calculator, also known as a reverse due date calculator, is the answer to the question when did i conceive? as it estimates when your pregnancy was conceived.

Use our pregnancy calculator by plugging in the date of your last period, the date you conceived if you know it, the timing of your ivf transfer, or your first ultrasound date. Calculate a conception date based on your due date, a dob or your last menstrual period.