Anyone measuring ahead ?!?


I'm 36 weeks and 4 days. My belly is measuring 38 weeks. I had an ultrasound done today and baby's belly is measuring 40 weeks and her head is measuring 38 weeks. She's weighing 7pounds 14oz. Did anyone experience anything similar and delivery earlier then expected. Doctor said if I go until my due date I'll have about a 10 pound baby! Really nervous.