QuestionHello. I am nearing my due date, which is January 30th. I have very irregular periods and at the beginning of my pregnancy I had an ultrasound done and it said I was 11 weeks and 2 days along.. GA was 14 weeks and I can't remember how many days. I was just wondering, when you have an ultrasound around 11 weeks, what is the margin for error on your date of conception? I have read in different places that ultrasounds can be up to 2 weeks off in either direction, but I have also read that the earlier you get an ultrasound, the more accurate it is.. so how many days or weeks off maximum can an ultrasound be at 11 weeks? And also, if my due date is January 30th, then what is the possible window of dates where I could have conceived? This is my first baby and I am new to how all of this works. Thanks for your help.
AnswerHi Sarah,
You are correct that early ultrasounds are considered to be very accurate, especially before 12 weeks. So I think you could rely pretty heavily on the once you had done at 11 weeks. So that means the due date you were given then should be pretty close, give or take a week.
I say give or take a week because not every baby is born at 40 weeks. "Full term" means anywhere from 37 to 42 weeks. And for reasons unknown, some babies arrive a little early, others a little late, even for mothers who could tell you the EXACT date they conceived!
I wish you all the best,
Anne S
