excessive amniotic fluid 3rd trimester?

Brooke
I went to ob today for a check up on my shoulder (see earlier posts) after receiving a vaccine that totally screwed my shoulder up. Sidenote: it was confirmed the vaccine was injected too high and the vaccine reeked havoc on the bursa in my shoulder and now I have to see ortho....BUT..... while I was there the dr said my belly looked way too big for 31 weeks. He measured my fundal height and I measured 5 cm above normal. Last week when I was there I measured 3 cm above normal. He has now ordered an ultrasound to rule out excessive amniotic fluid. Has anyone dealt with this? I'm totally stressing.