Expected Arrival Date
Once you have confirmed you are pregnant, your next question will be, "When will my baby be born?"
About 266 days or 38 weeks pass between conception and birth. This is the same as 40 weeks from the start of your last menstrual period (LMP) because ovulation normally happens about two weeks after the start of your LMP. You can work out the approximate date of your baby's arrival with calculations using the first day of your LMP. The estimated date of your baby's delivery (EDD) is therefore at 280 days (40 weeks) from the first day of your last period. The accuracy of this date is dependent on a regular 28-day cycle. If you have a shorter or longer menstrual cycle, your delivery date will probably be earlier or later. If you conceived immediately after coming off the pill it may be difficult to establish a firm date, but it can also be guided by the development of your baby.
Doctors use the EDD when monitoring the baby's development to ensure that there are no problems with the expected rate of growth. Unnecessary intervention can occur if too much emphasis is put on this date and doctors may decide to induce labor if they believe your baby is overdue.
Find the first day of your last period on the chart by looking for the month in bold type on the left hand side. Then look along the line until you find the actual date of your LMP. Below is the date of your estimated date of arrival.
Your Estimated Date of Delivery Chart