Pressure in abdomen when standing after bending. Anyone else?

I'm a Ftm and due 7/23. So I do a lot of bending at work to change garbage bags in small cans. I don't have the greatest knees so I still tend to bend at the waist. When I stand up straight from bending at the waist, it feels like a rock in the front of my bump, like baby curled into a ball and stayed right where the lowest point was. Does anyone else have this happen?

As a side note, sometimes when I go from sitting to standing, I have to go slow because in the front (where the legs meet the pelvic area), it is stiff and painful to move my legs untill it all RE stretches. Dr said it was just the ligaments, but that seems like a funny spot to me.