Pregnancy Tracking: Gestational vs. Fetal Age

We are happy to help explain how our app tracks your pregnancy.

There are two ways to track pregnancy, using either gestational age or fetal age. Gestational age is based on the first day of your last menstrual period, and is typically used by your doctor to determine your due date. This calculation technically includes approximately two weeks between menstruation and conception.

If you've been using a period tracking app you've probably noticed that your most fertile time of the month, when you ovulate, is a couple weeks after your period starts.

Fetal age is based on the approximate date of conception. This calculation eliminates the two weeks between when your period began and when baby was conceived. So it may appear to be two weeks later than gestational age. The fetal age is the actual age of the fetus, and is the timing that The Bump uses to track your pregnancy progress.

We hope this helps clear up any confusion. If you have any further questions, please feel free to email us at