Does costochondritis really feel like your having a heart attack?so how can i know which one?normal 2decho, ecg, stress test, chest xray

Check for tenderness: If all your diagnostic tests to check your heart are normal, it's likely that your chest pain is not cardiac in nature. That's great news! costochondritis can mimic cardiac pain but there is usually also tenderness at the junction of the ribs with the sternum at the chest wall. This pain occurs as a result if inflammation at this joint. Treatment with ice and anti inflammatory meds irecommended.

With all those tests: You should feel pretty confident of the diagnosis. Pain at yourcostochondral joints is generally reproducible with pressure on the joint(s) affected by the inflammation. And yes, the pain can feel very much like a heart attack.