Measuring huge!

So at my 24 week appointment, 4 weeks ago, my fundal height was measuring 3 weeks ahead of what it should. I was sent for an US which showed I had polyhydraminos and baby's growth was a little over a week ahead. They wanted to keep an eye on it do I had another US the next week which showed my fluid was still high but on the "high end of normal" and baby was still consistently a little over a week ahead. Today at my 28 week appointment my fundal height was 32 weeks!! Having another US tonight. I can't believe how huge and uncomfortable I am. GDM negative and I have only gained 10 to 12 pounds. My first son was nothing like this and was born naturally at 38+4 weighing 7lbs 7oz. That delivery was hard enough (2.5 hours pushing and vacuum). I can only imagine if this baby is huge how hard it will be! Anyone else had a similar situation?