I wouldn't go to Victoria's Secret either.

Just go into a specialty lingerie boutique and get measured. Or go to a Nordstrom department store and get measured there. That's where I learned that the reason why no bras fit me well is because I was a 32 D where I kept trying to fit into 34 C or B.

Boobs also grow well into adulthood. I was a AA until about 18 years old. I was a B coming out of college at 22. Now I've got big boobies that get HUGE when I am pregnant/breastfeeding...like 32 G!