We date pregnancies from the first day of the previous menstrual cycle. Actual conception usually occurs around two weeks after that day. Sometimes, it is difficult to remember the last menstrual period, or the last period may have been atypical which calls into question the true gestational age. We do ultrasounds to confirm dates whenever there is any question.
Select the date of your last menstrual period:
Your approximate due date is:
* Your due date is calculated by determining the first day of your last menstrual period. Substract 3 months from that date. Then add 7 days plus 1 year.