The ER Said That My Shoulder Probably Popped Out Then

The ER said that My shoulder probably popped out then back in on its own ( after being pushed down and trying to break my fall with my hand). It's been 9 days and it is still too painful to sneeze, cough or take a deep breath. the ER did take xrays of shoulder and found no breaks or fractures. Why is the area still so painful? Is it normal that I can't take a deep breath? Should I see a doctor & if so what kind?