I have smoked cannabis for about 6 months and stopped cold turkey 3 months ago. I had a dull sensitive pain in my top left lung and after showing no issues on the chest X-ray and ECG, doctor ruled that it was probably a muscular pain. Also I had lost some breathing capacity as shown by the PFT. The pain has almost subsided to nothing now, but I have another pain similar to a muscular pain that one would get when exercising after a long time, which is located above my right nipple and slightly right towards my armpit. Could this be any indication of a lung infection? Is it possible that something has gone unnoticed in the X-ray? Please reply asap, thank you!