This isn't an answer but em I am 10 and my breasts really hurt and blood is coming out of me I don't want to ask my parents because it's embarrassing please answer me I don't know what this is!?
The simple answer is hormones. Sometimes the hormones make your breasts hurt from one period clear through the next, other times two weeks before, other times the week before, and yet others just during, etc., etc. I wouldn't worry.