21, male. Get chest pain that goes when sitting down after lifting weights / running. Had ecg, 24h holter, exercise stress test, echo. All normal?

Anything. Could be a problem with skin, nerves, muscle, shoulder, lung, heart, or stomach. See your doctor for a more thorough history, physical exam and further evaluation. If she sleeps on her stomach she could have a neck strain that radiates pain to the chest or arm.