Top
sp
Home: Pregnancy Due Dates
Google
 

Pregnancy Due Dates
How to Calculate Due Dates

Calculating pregnancy due dates can be quite confusing.

There are several different possibilities. But for the sake of generalization, I will calculate the weeks of pregnancy by using the last menstrual period or LMP as day one. Most pregnancy wheels (the little cardboard wheels you see doctors and nurses use) calculate this way too. But there are several things to keep in mind about the due date.


  • Pregnancy wheels assume that you ovulate on day 14 of your cycle.
  • You can ovulate as early as day 8 and as late as, well there is no definitive answer to how late.
  • To get a true date, you can go by conception day, if you know it.
image aligned left

Here's a quick overview of calculating the due date.



If you cycle is basic with ovulation day around day 14, this will be fairly accurate.

Take the date of your LMP (ex: May 21, 2007) and subtract 3 months (ex: February 21) - then take that date (ex: February 21) and add 7 days (ex: February 28) Add the appropriate year - (ex: due date February 28, 2008 for a woman with an LMP of May 21, 2007)

If you wish to use your conception date (if it's not around day 14) then take the day of conception (ex: day 21 of your cycle) subtract 14 days from that date - then do the above calculation - you'll come closer to the actual due date that way!

Most importantly is to remember that every pregnancy is different. Pregnancy due dates are a general time that the baby may come. It's perfectly normal for a baby to arrive 2 weeks prior or 2 weeks after the established due date. Before or beyond that is considered either pre-term or post-term.

 

Subscribe to our FREE SiP Zine:

Email

Name

Then

Don't worry -- your e-mail address is totally secure.
I promise to use it only to send you SiP Zine.
Home
Fertility Charting
Fertility Tips
Gender Selection
hCG Levels
Infertility Issues
Natural Fertility
SiP Calculator
Early Pregnancy Signs
High Risk Pregnancy
Pregnancy Days
Pregnancy Due Dates
Birth Stories
About SiP
Maternity Card
Sign Up!
What's New
Build a Site
Contact SiP
Baby Wear
SiteMap
Privacy Policy

XML RSS
What is this?
Add to My Yahoo!
Add to My MSN
Add to Google