Miscarried 5 months ago and now having bad pains.

Hi, I miscarried 5 months ago, and I've had random amounts pain ever since. The pain is between my belly button and my hip bones on either side. It comes and goes, but some days it is very painful. The doctor I saw said that I would have some pain, but it gets to the point where I can't move. Sitting hurts, walking hurts, bending over hurts, and even standing for too long hurts. I have to do nothing but lay down when it gets to that point. I thought it would have worn off by now. I've had periods, but I've skipped this whole month for some reason. I'm really starting to worry. Has anyone gone through this? Or know anything that might help me?