Pinching pain directly over heart that comes and goes over weeks. all heart tests ekg, stress test, echocardiogram, and blood work normal. what could be causing?

Could be costochondritis an inflammation of the joint between the ribs and breastbone or pleurodynia an inflammation of the lining of the lungs (usually viral) . Both can be treated with ibuprofen/ Motrin if not allergic. May also be reflux- with or without H pylori bacteria could try famotidine- for the bacteria would need antibiotics . Would though continue to monitor and follow up with MD