Hi! I was sitting at my desk for about an hour 4 days ago feeling fine. When I got up I immediately felt discomfort in the area under my right shoulderblade. It has not gotten any worse since but not much better either. It hurts when I take a deep breath or lay on my back (only for a few seconds then relaxes). Also, today I seemed to aggravate it when I did something mildly strenuous using my right arm. It seems to feel best in the middle of the day but returns to its regular self in the morning. Is this something I should be concerned about or muscle related as I'm thinking? Thank you for your thoughts!