Hi ladies just wondering had an appointment with my Dr on Mar 4th and she said that I was supp st to be 16 weeks but I was measuring 20 weeks . I have an ultrasound coming up . If the ultrasound also shows a 4 week difference could they move my due date up ? I'm scared as I've always had big babies but they never started out big till the end then started measuring 4 weeks ahead . Sorry just confused