If the baby is measuring a little ahead at the ultrasound does that mean that your due date is recalculated or the due date remains 40 weeks from last menstrual cycle? I asked my doctor at my last ultrasound when he measured 12+2 and I was supposed to be 12+1. He said that one day doesn't make any difference and it is insignificant. But it is not a single day, because this went ahead in the previous ultrasounds as well. So now I am about 4 days ahead. On the ultrasound picture with the baby the due date is updated each time but I guess this is done automatically... On the other hand I did the double test and the fetal age mentioned there was the updated one, so that from the last measurement. I'm confused