Anatomy scan Questions

We just had our anatomy scan today! I’m 20weeks according to LMP but our numbers showed a little different. Babies head circumference measures 20w6d (so not crazy) but the AC which measures the babies Abdominal circumference measures at 22w3d. Sonography wasn’t concerned and doctor was going to review the ultrasound and call if he was worried about anything. Anyone else had this? Where the abdomen measures 2 weeks ahead?