S.L.
My brother just went through this with his 9 year old son. He had an x-ray, which the tech said was fine, but he was still complaining, limping around, and waking in the middle of the night with pain, so they continued to pursue it to find the problem. They had an MRI done and they found a spot on his bone which they said could be in infection, or a tumor. At surgery they did find it to be a tumor. It was called a Langerhands tumor - it is benign. HE IS FINE. Langerhands is more prevelant in boys, but I think it usually strikes boys older than your son. Please don't hesitate to pursue it if you think it is unusual. You know what is normal with your child.