What Causes Pain Around Tail Bone And Lower Leg Cramps?

I am having bad pain around my tailboine. It hurts to "tighten" my behind muscles. I also have been lightheaded for about 2 weeks and my lower legs are have been cramping. I went of an x-ray on lower back which came back normal. I am going to my obgyn on tuedsay. Can my systems be inline with a fibroid tumor?