im 36 weeks and my baby is small at 4lb 8oz also reduced movement so im going in thursday to have him good luck x.
Also you have to remember that ultrasounds can be off by up to two pounds weight estimates from an ultrasound are just estimated weight sometimes they can't measure everything like they're supposed to which can throw off the exact weight if your dr isn't worried too much you shouldn't worry you still have a few weeks for baby to put on some weight :)
Yes they should start to gain at least half a pound per week by this time :) don't worry though some babies are just smaller than others my baby weighed exactly that amount last Wednesday and I was 35+5 I go in again Wednesday to see if she's gained anymore