Pain right side spine one inch below shoulder blade around to ribs for months. back x-ray showed nothing. what could it be?

Check Gallbladder: Would see your doctor and see if you should have some tests on your gallbladder.

Thoracic pain: After excluding problems with your lungs (pneumonia), aorta, heart, esophagus, stomach, liver, gallbladder etc. You would want to consider a herniated thoracic disc. Any of these problems could mimic your symptoms. The chronic nature of symptoms suggests, to me, that nerve pressure could be causing. Especially if worse bending/twisting. Easy to confirm with mri. Treatment usually nonsurgical.