How to Determine Your Delivery Due Date

If you have recently found out that you are pregnant, you are probably anxious to know when your little one will make his or her appearance in the world. Contrary to popular opinion, you do not need to see a doctor or schedule an ultrasound in order to determine your due date accurately.

Pregnancy is 40 weeks in length, beginning with the first day of your last period, or 38 weeks from the day you ovulated. If you keep track of your menstrual cycles, you need only use a calendar, counting the first week of your period as week 1 and so on until you reach the 40 week mark, which is your due date.

If you visit a doctor in order to determine your due date, he or she will simply ask you the date on which you started your last period, then use a hand-held due date projection calendar. If you do not have even a vague idea of when your last period started, an ultrasound will be ordered in order to determine a due date. Beware, some doctors may insist on an ultrasound to determine your due date even if you are positive about the start of your last period. If you go through with the ultrasound and it gives you a date that is a few days before or after the calendar date, stick with your own. Technology is great, but it is not more accurate than a calendar when you are sure about your last period.

Keep in mind that your due date is only an estimate of when the baby will arrive, and your baby probably will not be born on that exact date. In fact, some statistics show that only around 20% of mothers deliver on their estimated due date (EDD). If you have a regular 28 day cycle, you are more likely to give birth on your due date. If your cycle is longer, you will likely to go past your due date, and if your cycle is shorter, you may give birth earlier. Also, remember that the average first-time mother gives birth 4-8 days after her due date.

Though you may be anxious and weary of pregnancy by your due date, you are not consider "overdue" until you have reached the 42nd week. It is good to keep this in mind throughout pregnancy to reduce the stress you will experience if you do not give birth by your due date.