There's really no way to know for sure, although just statistically speaking it's pretty unlikely someone your age would have a major structural heart defect, especially if there is no family history of cardiac issues at unusually young ages. If you really feel your symptoms warrant such you should probably just go to a cardiologist. Someone complaining of persistent chest pain would probably warrant a stress test and echo. If the echo shows your heart to be structurally normal and the stress test produces a normal response that will be that. If the stress test is abnormal they might start to suspect coronary issues and may do an angiogram. The echo would really be the biggest test, though. It would easily reveal if your heart is dilated, hypertrophic, or if you have any valve or aorta issues, as well as identifying any of the relatively rare congenital cardiomyopathies (HCM, ARVC, etc) that could cause symptoms. So, if you have a PPO and don't need a referral you could just make an appointment with a cardiologist. But like I said, it's all so unlikely at your age, the tests they would run are very costly and time consuming, but if your symptoms are really that bad, or you are really that concerned, making that first cardiologist appointment ought to be your first step.