36 weeks pregnant measuring 34 weeks??

Ta

Hello everyone, I just had my OBGYN appointment and I was told I was measuring as if I was 34 weeks pregnant. The week prior I was 1 week behind as well. But the dr didn’t think much of it and wanted to check the next weeks reading. So now that My baby boy is measuring 2 weeks behind the dr has scheduled me for an ultrasound to see what’s going on. If anyone can please tell me if they have any similar stories or know anything good or bad. I would greatly appreciate just so I know what to prepare myself for. They also told me that he is head down already as well, not sure if that affects it either.