Mild Chest Pain Every Time After Smoking. What Could It Be?

Okay so im 21 years old male, height is 6 ft and I weight 140. So ive been smoking since I was 18 almost everyday sometimes once a day sometimes I dont smoke . The other day after I smoked I felt a mild chest pain in my right side it wasent so bad it was mild for like 2 mins. The next day I smoked I felt a mild pain in my left side. Ive stopped smoking since and I still kind of feel it But not the same. Any idea what it could be?? Really appreciate it.