Due date

Your due date is not a prediction of when you will have your baby. It's simply the date that you will be 40 weeks pregnant. Few people give birth on their due dates. Still, establishing your due date — or estimated date of delivery — is important. It allows your health care provider to monitor your baby's growth and the progress of your pregnancy. Your due date also helps with scheduling tests and procedures, so they are done at the right time.

To estimate your due date, your health care provider will use the date your last period started, add seven days and count back three months. The due date will be about 40 weeks from the first day of your last period. Your health care provider can use a fetal ultrasound to help confirm the date. Typically, if the due date calculated with your last period and the due date calculated with an early ultrasound differ by more than seven days, the ultrasound is used to set the due date.