My doc says as long as its within 2 cm. I was 30 1/2 wks measured 32 cms, so I was measuring 1 1/2 wks/cms ahead. I'm due june 11.
Was it the height of your uterus that they measured? Mine was a week ahead once, but when I went back the next time it was back to where it should be. My friend's baby measured a week ahead by ultrasound, but they didn't change the due date because it was only a week. You baby could just be a little bigger than average. I don't see how they are able to tell with the tape measure. I always find it weird that they measure me with it.