Changing my due date

My doctor told me today that she wanted to change my due date because at my ultrasound at 10 weeks, I was measuring a week behind. I really have an issue with changing the date because I know exactly when I ovulated.

I was taking my temps and using a fertility monitor, so there are no surprises there. I did tell her that, but she still wanted to change it. When I told her that the due date predictor online (using my date of ovulation, not the date of my last period) said I was due on Christmas Day because of it not using the date of my last period, she caved a little. We are now saying I'm due on Dec. 27, which is a compromise.

I really think I'm due on Christmas Eve, to tell the truth. "T" always measured behind and was small at birth. I think this baby is probably going to follow suit. I told her that I didn't want to go overdue because I had heard horror stories about that. She said in their practice, they will no longer allow anyone to go past 41 weeks due to those kind of stories. She said it used to be 42 weeks. She said some doctors are still allowing women to go 10 days past their due date, but they don't want to take the chance.

She also said that I probably won't go to my due date anyway. At my last appointment, she said they would probably induce me a week early due to my history of pre-eclampsia. I hope she still plans to do that.