If you have just learned you are pregnant, a million questions are probably racing through your mind. Many of these probably revolve around your due date: how accurate is it, how do I find it out, and will it change? Although the exact date your baby will be born is nearly impossible to calculate, you can easily learn how to calculate your approximate due date based on your last menstrual cycle.
Keep in mind that due dates are only estimations of when your baby will arrive — only a very small percentage of babies are born on their given due dates. However, knowing the approximate due date of your baby is an invaluable tool that helps both you and your doctor monitor the progress of your pregnancy.
Keep in mind that your doctor may change your due date as your pregnancy progresses. This is because as the doctor collects more information about the way your baby is growing, they will have a more accurate estimation of when he or she will be born.
First things first — figure out the date of your last period. This date will be used in both methods of calculation.
If your menstrual cycles are roughly 28 days long, you know the approximate date of your last period, and you don’t want to calculate your due date by hand, you can use our website’s very own automated due-date calculator.
Once you know the date of your last period, you can choose one of the two following methods to manually calculate your due date. Using the last known period date of August 1st, 2015, this is how both methods would work:
- Add 40 weeks or 280 days from the date of your last period (May 7th, 2016)
Method 2: Naegal’s Rule
- Add seven days to the date of your last period (August 8th, 2015)
- Subtract three months from this date (May 8th, 2015)
- Change the year if necessary (May 8th, 2016)
Both calculations are nearly identical, only varying by a single day.
Figuring Out Due Dates for Women with Cycles Longer or Shorter than 28 Days
If your menstrual cycle is usually longer or shorter than 28 days, you should consult with your doctor to get a more accurate due date estimation.
At South Lake OB/GYN and Advanced Surgery in Clermont, our doctors will work with you every step of your pregnancy. Our patients are our top priority, and we’ll help you have a happy, healthy and comfortable pregnancy. Contact South Lake OB/GYN today to schedule your consultation.