Heather
Ask you doctor about further lab tests. Do you have a family history of arthritis? Perhaps you could ask for a ANA, Rheumatoid Factor, HLA B27. It seems like it would show up on xray but maybe it is muscle or ligaments causing your pain. It sounds pretty frustrating. Have you been taking muscle relaxers and NSAIDS (non steroidal anti-inflammatories)? Does it get better if you apply heat/cold? Do you do any stretches. Does everything else check out okay heart wise? You may want to make sure first of all that you can get some good nights of sleep with medication and then work on improving your general health. If you are tired and stressed you will hurt more.