I had an ultrasound done yesterday, and the Dr is concerned because they have me at 29 weeks pregnant and the baby s head circumference is measuring at 26 weeks, and abdomen circumference is measuring at 30 weeks. My Dr moved my due date up a week when I was 12 weeks because the baby measured at 14 weeks. I am POSITIVE of my LMP date and ovulation dates because this baby was planned and we were using ovulation tests and I kept track of my dates. Could this change of date be to blame for the measurments discrepancy, and if not, how common is this and what could it mean?