Around Just 4th, I started having shoulder pain with my left shoulder. I figured I slept on it weird since I was sleeping on my left side most of the night. After a few weeks, I didn't notice it as much and began working out again. A couple of days later, I was getting sharp pains by moving my arm/shoulder certain ways. About a week ago, I tried doing a pull up to see how my shoulder felt, and about half way through the upward movement I could feel the pain flaring up.
During normal day to day activities (sometimes lifting/moving computer equipment, it doesn't bother me. At night, however, I can't lie comfortably on my left side and even when lying on my right side, my left shoulder can cause discomfort if not positioned just right. As best I can tell, the pain mainly feels like it's coming from muscle 7 on this picture
. It's more "on top" of my shoulder.
Any ideas what this could be? I figure I'll be heading to a doctor soon if I can't figure out what's causing it.