I just found out something that strikes me as odd. Due dates are calculated based on the day of your last menstrual period, not conception. You don’t conceive during your period though, you conceive during ovulation which is about two weeks later. Does this mean that actual pregnancy is more like 38 weeks instead of 40? Or does it mean that your baby is not really due for another couple weeks after the doctor says, and that’s why so many babies are born past their due date? This is so confusing to me!