hi - sorry to hear about your situation. if you don't get any answers in this forum, you might want to try the "breast cancer support" forum. not because i think you have breast cancer, but i'm sure there are women there who have a lot of experience they can share. good luck :)
I had almost exactly the same thing. I had a "knot" under my right arm. It was not hard...and it would slightly move around if I touched it. It was very tender to the touch. I went to the doc, and had it removed. It was called "lipoma"...which they explained to me was displaced breast tissue. This is not uncommon. Believe it or not, when I had my son, the area that had been removed began to swell when my milk came in. Ugh! However, that lump went down.
I've never had a cancer scare, but several in my family have, and I've always heard (maybe someone will correct me if I'm wrong, because I certainly could be) that the lumps you feel that don't hurt...the ones you don't know are there...are the ones to be concerned about.
I hope that you find the info you need...I thought it might be encouraging for you to hear that my story was similar, and everything turned out great!
MAKES ME FEEL A LITTLE BETTER...THANK YOU VERY MUCH
ALREADY WENT THROUGH THAT 2YRS AGO. HAVENT HAD CAFFEINE SINCE THEN...BUT THANKS FOR THE SUGGESTION!!