Baby Due Date Tool
Your Results
Since your last period was on , your baby's birth date is on or near .
How is a baby's birth date found?
Standard Dating Method
Doctors have found that a baby stays in the womb for about 266 days. This is from the day you became pregnant. It is also 280 days after the first day of your last period. A woman’s normal cycle is 28 days. Her eggs become fertile on day 14. So the egg could not be fertile until two weeks after the first day of the cycle.
Most doctors know that many things affect a due date. Your doctor can use other ways to help find your due date.
References
Nemours Foundation, Pregnancy calendar, KidsHealth, 1995-2003. Accessed at: kidshealth.org
American College of Obstetricians and Gynecologists, What to expect after your due date, 1999. Accessed at: ACOG
Author:
Lambert, J.G. M.D.
Online Editor:
Rademaekers, Ed
Online Medical Reviewer:
Dolan, Mary MD
Date Last Reviewed:
12/6/2007
Date Last Modified:
3/17/2008