little brown spots and lump in my breast

Hi, i am 17 years old and i recently started to notice a lump in my right breast, it has gotten bigger and whenever it has pressure on it or i squeezed it hurts for a minute or so after. my breasts have gotten alot more tender and hurt more then they used to. I know that i am growing so i didn't take this to the docter but now little brown spots have formed around my nipple around 8 the size of the end of a pencil (the right breast) and not on my left one. I've been more tired lately and get nausea and migraines lately. A couple weeks ago i had this really sharp pain in my lower back and around where my appendix or kidneys are for 4 days and it went away.

[Cleveland Clinic]

Dear sk8192:  Breast cancer is very rare (nearly unheard of) in women in their teens.  However, breast pain is very common.  This is often cyclical (occuring at certain times during the menstrual cycle) and may be accompanied by lumpiness.  Regarding the other problems you mention, you should bring them to the attention of your doctor for evaluation.