When I walk it's fine or if I have been standing it doesn't hurt. Really the only time it hurts is when I'm in my car driving. It's like thr very bottom of my spine. If I roll my hips forward it doesn't hurt as bad. this has been happening for about 3 weeks and I'm starting to get scared. I can't think of anything that ihave done that would have bruised it. my brain is starting to go to the movie 50/50 where he had cancer on his back. But my rational side says if it was cancer or a tumor it would always hurt. Right????