How accurate is my due date?

Your due date is an estimate based on standard pregnancy dating methods. In fact, a medical review of Naegele’s rule and the length of pregnancy highlights that the standard 40-week timeline is just a guideline, not a strict deadline. 

Personal factors like your height, weight, and menstrual cycle can all change the actual length of your pregnancy. Babies aren’t always born on their due dates, so don’t stress if you cross that 40-week mark. Only your doctor or midwife can give you a more definitive timeline using physical check-ups and ultrasound scans.