I have really small boobs but I’m a D cup.....

So I measure 31” under bust 35” overbust making me a 32D. Whenever I’m asked my asked my bra size and say it people act offended or like I’m lying... I know it’s stupid, but I find it annoying. It’s not my fault I wear the correct bra size that is meant to support me. Studies done on breast size are according to this or that are so inaccurate. I know I’m D cup but I look like and A or B cup. So I know when people say “can’t be less than a d cup or its unattractive” their not referring to me they are referring to what they think a d cup looks like.