Im 14 and im worried about a small lump in my . Can anybody help?

hi im 14 and today i felt a small pebble like bump in my . more so like under the nipple. shouldi be worried cause i really dont know. i dont have the kind of relationship with my mom too tell her im worried about this. i went on some websites and they said wait until after your period to see if it disapeared. should i wait? do i tell my mom? i have a phyical at the end of the month for school would my doctor find it then or shouldi tell her? im really confused and i need some help. im scared