Should i wear a bra to gymnastics?????

okay i barely have im just starting to grow. im basically flat chested! but i wear a bra ion a daily bases beacuse my niples will show if i dont. in one of my leotards my s look wierd:\ and im uncoforatble with it. My friend whos 14 says i should wear one cuz later on theyll droop down:( what do u think?????????