Pinching feeling in chest and chest pain. occasional referred pain in left arm or back. ekg and stress test normal. ultrasound normal. what is it?

I know what it isn't: It isn't your heart. Could be musculoskeletal. Since you've already seen a doctor, you should go back and have him/her look for other causes, none of we which are likely to be serious. There is a condition called pericarditis, inflammation of the sac surrounding the heart, that can produce chest discomfort, but I can't sort that out here, but ur doc can. Good luck.