With DS, I measured two weeks ahead consistently, but I knew that the EDD was two weeks off. They didn't listen to me, telling me that the early fetal u/s is the most accurate. While I generally agree with that, I knew that in my particular case, it was not. When they started talking about scheduling a c-section at my 33 week appointment, I fired that OB and sought a second opinion, who, without even hearing the correct date, said it. I delivered DS the day before his EDD.