Yesterday out of no where during my walk home from school my shoulder started feeling uncomfortable. I figured it was the school bag that I was carrying, even though it wasn t even that heavy. When I got home, it was very sore and got to the point where moving my arm even the slightest bit cause very sharp pain. I decided to take a nap and when I awoke the sharp pain was gone but it was still sore. Today, it s STILL sore and certain arm movements or lifting even light objects causes pain that is bearable, but it s still uncomfortable. What should I do??