How do I calculate my due date?

Your due date is an estimation as nobody can know exactly when you ovulated and conception took place. Conception takes place approximately 2 weeks after you have had your last period. We therefore work out due dates based on the first day of your last period.

From the first day of your last period, add on nine months and seven days. You can expect your baby anywhere between two weeks before this date and two weeks after this date. Two thirds of babies are born within ten days of their due date but only about 4% of babies are actually born on their due date. It is therefore more accurate to refer to it as an ESTIMATED due date (EDD).