Hello, I have a hard painful lump on my collar bone, it could be my collar bone, but I'm not sure yet. It burns if I put RUBA535 on it. I also have had my root canals done and I'm not sure if its caused by that. I have not fallen or gotten hit in any way, I have resently got a new job and I'm quite tired because of the time change on my job, but that is normal. What could this lump on my collar bone be? Thank you.