bra size

im genuinely confused over my bra size. and how bra sizing works in general. ive tried using the bra that fits(?) calculator that everyone uses and it told me that i was a 30something C?? im not sure if im measuring wrongly or what because that cant be right. like, my boobs dont even touch when i try squeezing them together. i am legitimately genuinely seriously very very small. i just want a bra that will give me some lift and ive been trying to bulk to gain weight. so- 1) is that calculator actually accurate for the flat girls? 2) any bra recommendations for flat girls looking for a push-up effect?