Rock Hard Bump While Standing?

Suzanne
I'm 40+6 and when I stand my bump is almost rock solid. When I sit, the sides go a little softer except for the left side, which is the side he sits on. He's moving a bit but not too much. Also when I'm standing there's a lot of pressure down there, almost like lightning pelvis. Should I be worried about low fluid levels or could these be contractions of some sort?