Your ‘due-date’ means the date your baby is expected to be born. Your due-date is an estimation, based on…

  1. the date of conception (aassumed to be the first day of your last menstrual period plus 14 days)
  2. the assumption that all pregnancies are 38 weeks long (from date of conception, or 40 weeks from date of last menstrual period).
  3. data from any prenatal ultrasounds you’ve had (baby’s gestational age corresponds to measurements of key parts of his/her body, such as the head and femur).

Only 5% of babies are born on their actual due-date, with a majority of first babies born after their due-date.

Due-date Calculator – A lot of sites will calculate your due-date, but this one is superior because it takes into account the length of your cycle as well as the date of your last menstrual period (thus calculating a more accurate due-date). By the U.S. National Women’s Health Information Center. Also gives a summary of the 3 trimesters of pregnancy.