what is this?

Samantha
I'm 33 weeks pregnant and the last few days I've had really bad pelvic pressure that hurts to walk, back pain, and last night I couldn't sleep because of a constant burning pain in my lower belly.. call me crazy but my dog has been in my lap and all up my butt since this has happened like she knows something is going on and it's creeping me out! Any idea what this could be?