Painful movements = low fluid?

Sagen

I am going to call my doc to ask, but I was curious so I thought I would ask here as well until they call back. Lately his movements are really painful, even when he is just shifting around. I wonder if it is a sign of low fluid with the thought that there is less cushion between me and him. He moves a lot and has been measuring ok so I am probably just freaking myself out. Any input though?