Hello, I'm a 31 year old male, 5'5" 170 lbs, with no medical problems to speak of. I've had a lump in my armpit for a couple of months now. It seems to come and go, swelling to about the size of a grape at it's most inflamed. While it's that large it's very tender, and as it shrinks I feel only a tightness in my armpit. It recently broke, oozing blood and pus. Is this something that I need to worry about?