I have a pea sized lump in my armpit that is hard, painless, unmoveable and a bit below the skin (I can't feel it unless I push on it.) Is this something to worry about? I am going for my annual mammogram, so I figure that should take care of it, but I read that a regular mammogram won't help with under the arm. Should I mention this to my doctor? He's 45 minutes away so I don't go there unless I really need to.