Chest pain w heavy exercise, ekgs-echo-cta-cbc-cal score(0), all normal, no sob - just burning chest/ab pain with heavy exertion, could still b heart?

It is unlikely that: your extensive workup would miss a cardiac etiology for your discomfort. In addition the discomfort you describe is atypical for cardiac pain. Sounds like musculoskeletal discomfort from contraction of these muscle groups rather than your heart. Make sure you adequately stretch and warm up before exercise and are very well hydrated.