My doc is putting me in physical therapy.
I have something like that around my hips and lower back. That is b/c your pelvis is stretching and pushing back into the lower portion of your spine. I've been going to the chiropractor for that and has done a WORLD of difference. It was so bad I couldn't stand. It is very common to have a sore back. As long as your not cramping or bleeding, you don't need to stress. It's very common for that. You can always call your doctor and see what he or she says. Just try and relax and maybe have a spouse, friend or whoever to rub it and see if it helps. You can even try an ice pack, if its swollen it will bring the inflammation down and take off some pressure. Good luck!