Can someone help me please?

about a month ago i was helpin my bf move and hurt my rotator cuff. than two weeks later i was reachin for somethin with the arm of the shoulder and heard a pop in my shoulder and some bones move, my shoulder felt better after that. a few days after that my shoulder flared up real bad it hurt so much i almost cried. i went to doc got shoulder immobilizer and cortizone but not into muscle. than today i moved my shoulder and again some bones moved in it and i feel way better. will it flare up again, why does this happen?