The former Destiny`s Child singer first considered having a breast enlargement operation when she was just 17, but decided to hold off for a decade to boost her A-cup to a B.
Kelly, 29 told British station BBC Radio 1: "When I initially thought about it, I was 17. That`s a ridiculous age to make a decision to do something different to your body. I`m really proud of myself that I waited."
But she admits her decision to wait didn`t always feel like the easiest.
She said: "That`s 10 years I waited. That`s 10 years I was like, `I hate this top. It does not fit. I hate this top.` "
Kelly is so happy with her cosmetically enhanced figure, she hasn`t ruled out having more surgery in the future.
She told Closer magazine: "If my butt is falling I`m going to pick it up. I`m not against it."
Despite having no problem with surgery, Kelly says she would never have Botox.
She said: "I`d never have Botox - no way. I don`t want needles stuck in my face, that`s going to hurt. And I like to have expressions!"