Hi. It's normal for males your age to have tender lumps under the nipples. Those are breast buds, and are a result of a sudden increase in sex hormone levels in your blood. This is part of normal pubertal development and is nothing to worry about. Besides, breast cancer is rare in males, and rarer still in males your age. So I wouldn't consider cancer in your case.
i am 13 year old male help me i got a very big lump under my fight nipple because of me and my friends mucking around and giving each other frosstys and now i have a large lump