What Causes Pain And Discomfort In Middle Of Back After Quitting Smoking?

i I have stopped smoking 9 weeks now and I am getting a weird feeling in the left side of my middle back its wen I move my body its like a shock in my bk and it makes me jump not a pain as such its really hard to explain kind of a pricking not all the time when Iturn over in bed or jault quickly its very strange could it be my lungs getting clear. Thankyou