I have a third/supernumerary nipple below my left breast and it is very small and i think it has forever been there. It has always been little painful and I keep checking for rash and lump but I don't find any, but on certain days its more painful and these are not always the days before, during or after my period also sometimes wearing bra causes pain around it. Should I be worried because it has always been slightly painful since I noticed it in my school days and I am almost 25 years old now.