Hi thanks for contacting HCM.... You have only complain of chest pain... And you are regular smoker.... It might be muscular pain.... But before labelling it muscular pain I would like to suggest few investigation.... Smoking can lead release of elastase that damage lung elastic tissue. ... So you might have early stage of fibrosing disease or obstructive disease .... Investigate with spirometry for rule out lung capacity and disorder ...... Also do EKG to rule out cardiac cause (Although chance less) If nothing serious than fibromyalgia like muscular pain is the cause ... Also look for if any gastrointestinal cause present because it can lead reffered chest pain.... Consult pulmonologist with keeping these in mind .... Take care ...