I had this same thing!! Please, if you can, go see a chiropractor. Ask him/her to check your "pubic symphysis". It's the joint at the front of your pelvis, and during pregnancy it is normal for it to come apart a little, but with mine I couldn't walk at all, it hurt SO bad. My chiropractor said it was the worst case of pubic symphysis dislocation that he'd seen in a pregnant woman, and an adjustment fixed it.