New pregnancy pain?

I'm 4 1/2 months pregnant. I've been a bit more active today than usual trying to clean the house before family arrives from out of state.

Every time I sit, stand, or lift a foot up off the ground more than four inches it feels like my pelvis is cramping, it's quite uncomfortable. Is this just another wonderful pregnancy thing?

I'm constipated and stressed the smurf out if that has anything to do with it.