Hi im a 12 year old boy and i have a button like thing under my left and right nipples could this be brease cancer?

No, puberty: Boys go through a period of slight breast development at puberty and these feel like buttons, exactly as you described. It is entirely normal.

No: About a half of males will undergo a transient nipple/breast enlargement at he onset of puberty. Normally it will resolve slowly as other hormonal changes kick in over about a year. Carrying around extra weight can aggravate the issue as fat can masquerade as breast tissue. Check with your doc if you want to be sure.