Tiny cup size..

I am an adult and my bra cup size is 36a but I only fill half the cup... I am very small. I got tired of people asking me if I am anorexic so I bought a padded bra. It takes you up 2 cup sizes so I look like a B.. Here's my problem. I have to tell before getting married. I'm having a hard time figuring out how to tell. What's your advice? I don't want to surprise him by being so tiny so warning is needed.

Are you a small cup size? Has a guy ever been negative about it?