My brother was born at 31 weeks and weighed 2pds 1 ounce. And he's 7 now :) I think your fine
My daughter didn't move much here it was from the position of her umbilical cord, when I had her she was just fine keep your chin up I'm sure all is well
My daughter was born at 39 weeks 3 days and was only 5lbs 7oz but she was in perfect health! Some babies are just smaller than others that doesn't mean anything is wrong with your baby also at 36 weeks doesn't have much room to move I'm 37 weeks and my son has calmed down a lot when it comes to moving
They told me both my sons were small, but neither of them had issues other then unrelated breathing issues. My first son totally stopped growing at 35 weeks and was only 5 lbs 15 oz at birth, now he's a healthy rotten two year old, he's still small weight wise but he is healthy