115/72 blood pressure having light chest pain no other symptoms what can it be?

Multiple causes: Chest pain can occur for a variety of reasons; ischemic heart disease, esophageal spasm, dissecting aortic aneurysm, mitral valve prolapse, pericarditis, pulmonary embolis, pneumonia, chest wall pain (costochrondritis), pleurisy, etc. Your BP looks good and since you have "no other symptoms" the cause is most likely benign. If other symptoms develop seek prompt medical attention.