Hi. I just notice a bump in my right armpit . Its not visable as far as I can see and it hurts lie a deep bruise by its not a bruise .. it hurts to move my arm and doesn't hurt to just keep my arm still. My arms and shoulders have recently been really sore. Kinda like muscle aches. I don't know if that has anything to do with it. But its worth. Mentioning. -alyssa almost 13