I know for a fact that I got pregnant on either January 1 or January 2, 2011! These are the only possible dates! I do not remember my last menstrual period. The doctor says that I am due on September 25, 2011. Is this correct? I calculated from either the 1st or the 2nd and this due date only puts me at 38 weeks by the time I am due. How is that possible? How many weeks am I technically?

Without knowing your LMP it's hard to say effectively.

However, thanks to my handy dandy gestation wheel (the one the doctor uses to estimate your due date), it appears you conceived approximately January 4.

Thank you for your response. But the doctor says I am 7 weeks and 2 days pregnant. I got pregnant on the 1st or 2nd of January so wouldn't that only make me 5 weeks and 2 days?

Pregnancy is most often dated with gestational age, from the time of your last period. This is because they won't know for sure when you actually conceived. It could be just a couple of days after your period ended, it could be two weeks after.

You have a better idea because you know the time frame you had sex in. Although this still doesn't give you the exact date you conceived, only when you had sex that led to conception.

Even with that knowledge, the dating usually stays the same. You may find they will change your due date slightly when you have an ultrasound at some point and get a better idea of how far baby's development has progressed.

Going with gestational age instead of fertilizational age allows for a window of time at the end of pregnancy for you give birth that would be considered the norm... roughly 37/38-42 weeks.

Thank you DoulaLC. So, do you believe that given my information my due date is correct as September 25, 2011? Making me around 7 weeks pregnant?

Yes... the due date is 40 weeks from when they assume your last period would have likely been if you conceived early January. You are technically closer to 5 weeks from actual conception, but the pregnancy is dated as 7 weeks from your last period.

I know it doesn't make sense to do it this way when you definitely know the time frame you had to have conceived, but that's what is used. Odds are, when you have a scan later on, they may possibly change your due date a bit.