They said he "has tiny legs"

I am 37+3 and had an ultrasound yesterday because my belly is measuring a few weeks behind. The tech mentioned that his legs were all curled up and when we saw the OB, she said his femur length was in the 3rd percentile. Now we are going to have another ultrasound next Tuesday and have to wait until then for more info. They checked his head and belly measurement and didn't mention anything "wrong" with those.... And we had a clear quad screen during the first trimester. Anyone out there have a similar experience?