I would get it checked out, doesn't sound good. I took a nasty fall backwards about 5yrs ago, landed on my left elbow, driving my shoulder forward. Cortisone shot and 4 months of rehab. Now I do shoulder exercises with dumbells to help keep the shoulders strong. If I lay-off for awhile I can tell. Feels like my left shoulder starts getting loose. I wasn't able to shoot traditional for a couple of years, hurt, and went back to a compound. Dr said if my shoulder muscles hadn't been strong from shooting archery I probably would have tore my rotator cuff. Hope it's nothing serious. When your able to, look into doing some shoulder exercises to maintane your shoulders and warm up before you shoot. Good luck.