I have a strange swelling towards the end of my collarbone, sort of starts at the jutting part of my collarbone and wraps up, like if it continued on it would wrap up and over the muscular part of my shoulder. It's just puffy skin, nothing hard, nothing rubbery, just puffy skin. the only way I can tell it's different is that the other side doesn't have the same structure. I noticed it last night and decided to sleep on it. It doesn't appear to have gone down. Is this muscle related or should I see a doctor?