Blood tests and ECG were normal but I still have heart palpitations. I've stayed away from caffeine but they won't stop. What could it be from??

Palpitations. Palpitations have many causes from anxiety through anatomic and physiologic abnormalities. The feeling of bounding usually relates to the volume of blood pumped with each palpitation. There is no simple single answer for the question. If you're bothered by the feeling should consult a dr. To see if the problem can be clarified.