My breasts are very small and I look flat every time I wear swimsuit

Hello,I'm 15. I got my periods whn I was 10.yeah Ikw it's early bt after 5 years,my boobs just grow little,n nw my boobs vry small n it looks flat every time I wear swimsuit.i always made fun by my fren n I feel embarrassed n annoy abt it . Is there anyway to make my boobs grow ,or does it stop growing?help me pls