I am about 37 weeks pregnant and I am measuring at 41 weeks pregnant and my baby is measuring at 41 weeks also. I have talked to my Dr. But she says she ain't changing it she is sticking with the very first date. So with that if me and my baby are both measuring at the same and almost a month over what they say I am could my due dates be wrong??

It can vary from doctor to doctor a bit, but usually they stay with what was determined on a very early ultrasound.

The reason for this is because babies generally follow a fairly predictable rate of growth and development early in pregnancy... often just several days difference. Late in pregnancy, growth rates can vary a bit more, so determing size is not as accurate. Measuring your fundal height is not wholly accurate at this point either. Factors that can contribute are number of pregnancies, amount if amniotic fluid at the time, location of placenta, position of baby, etc, as well as possible size of baby.

If you had been measuring ahead awhile back, and continued to do so, they may have altered dates a bit at that time, but this late, it doesn't happen as often.

Your doctor can do some evaluations, that may ease your mind, on how baby is doing. Is your current due date from your last period or from an ultrasound?

No, I would not say that.

Due dates come from estimated conception dates, normally based on your last reported cycle. So when was that last period.

Also, size is a average, there are babies larger than average, and smaller than average, that is how an average is gotten.

And to be blunt, the baby will start labor and come, when the baby is ready, So the actual due date is normally just up to when the baby decides to come out.