Ok I'm no expert of course lol but I did (an am still doing with my third baby) yoga, they make pregnancy videos of yoga that helped me out a lot!!!! Just make sure it's a low impact video if you have never done yoga
Have you tried taking a warm/hot bath with the stuff that relaxes your muscle. Sorry, I don't know What they're called.
I have tried stretches and walkS and every time it hurts worse when I'm actually walking around and doing stretches my pelvic bones hurt so bad
I would say stretch to loosen up your muscles?