I've been feeling this pain on the right side of my chest whenever I take a deep breath or sneeze. It's been going on for about two months, and sometimes it feels mild, but other times it's sharp. Plus, it hurts more when I do anything physical. The pain even goes up to my right shoulder and back. I don't have a cough or sore throat or anything like that, just this weird pain. What do you think it could be?