Hi, around 9 PM tonight I started to feel a slight pain in my right nipple. Eventually my left armpit began to hurt, and it has been really frightening. I know that my right breast area has a tender bump because I have begun the process of puberty, but I am at a blank as to how my armpit is having this pain. I'm 12 years old, and really hope this does not mean I have lymphoma or some type of cancer. I can't find the bump yet, but I would like some sort of information before I head off to the doctor. Thanks, and ignore the grammatical errors as I am typing on a mobile device.