30+4 and hurting really bad.

I have been getting really bad pains in my groin area and my pelvic bone. When I moved before to try to turn over on bed I felt my pelvic bone grinding and I could hear it. It was one of the worst pains I've ever felt in my life. There are times when I stand that it feels like my pelvic bone collapses in on itself. I've tried talking to my dr about it and she doesn't seem to have an answer. Does anyone have any idea of what this could be?