Hi Skorpy
For the past few weeks your body has been releasing a hormone called relaxin. This hormone causes the joints in your body to loosen in preparation for birth. One common thing that women often notice is a feeling of their legs not fitting into the hips properly.
Another common problem is what you have. Your pubic bone is actually two bones joined in the middle. This joint has been loosened by the hormone relaxin. When you move these bones rub together causing the pain. There is no real treatment for this except perhaps panadol. When turning over in bed try to do it slowly and in stages if possible.