Small boobs

I'm always so stressed and self conscious bc I have been a size 32a since 7th grade or so and I'm now a senior. I can barely fill that cup. I've already hit puberty, I got my period in 5th grade. I only weigh about 97 lbs but my hips and thighs kinda have some fat on them so why don't I have a little bigger bust? Will they ever grow? Do I need to gain weight? I eat a lot and I just seem to never gain anything, the only time I do is when I'm exercising and I gain muscle bc I have none whatsoever and that's when I finally got about 100 lbs.. Guys definitely don't like small boobs and I don't either. Is there anything I can do?