How is your estimated due date calculated?
Your estimated due date (EDD) is calculated by adding 240 days (which is equivalent to 40 weeks) to the first day of your last period – this is based on a regular 28 day cycle.
Please remember that your EDD is exactly that, an estimation. Only 5% of babies come on this date, and seeing as babies have their own time schedule you may be kept waiting a little while longer than you had thought! Be assured though, your baby will come out eventually, some babies just like to bake a little longer. This is perfectly normal.