If you go to a cardiologist for chest pain, they will rule out cardiac causes. This usually involves an EKG, stress test and echocardiogram, sometimes a heart cath. This is done to stratify your risk of cardiovascular events -- heart attack, stroke, sudden death. For the symptoms you describe, the risk based on history is pretty low. Cardiac or heart related chest pain is rarely described as "sharp" or "stabbing" and is usually worsened by activity, improved with rest.
Other causes of chest pain are often difficult to give an exact cause to. I know this is frustrating, but there is often not a great answer. The one thing that always comes up is anxiety and I find that a lot of people admit this is a real possibility when it brought up. It could also come from lungs or pleural sources (lining around heart and/or lungs).
I hope this helps, thanks for posting.