Chest pain is a vague complaint. It may be related to the heart and a chest xray would image the size and shape of the heart although it is not capable of visualizing the arteries of the heart. It will however visualize the aorta or large artery as it exits from the heart and the aorta is sometimes but not often a source of pain. Infections of the lungs and inflammation of the covering of the lungs may cause chest pain. Pathologic changes in the ribs may lead to pain and these may be found in those with cancer. Damage to a segment of the lungs due to a blood clot may also lead to pain. There are more reasons but I believe that this will give you some idea of the possibilities. I would not be alarmed as the physician would have told you if something truly serious were being considered. I wish you the very best of health.