Flat chested with a bathing suit season coming?? Oh no!?

Ok you can say all you want about a 12 yr. old flat chested girl. Its embarring but I wear padded bras and that helps. ok so like I know its swim suit season soon where I live and I dont wanta be flat chested in a bathing suit. I know I shouldnt care about my looks but i do. I want to get a bathing suit that has padding at the bust, but i cannot find a good quality cheap one that will fit me. I also realize that no cheap one will be of good quality but what the heck. I am really small, like only 15-20 inches around by bust. I am estimating....so yea a site where I may find one would be amazing. Thank you all!