fluctuating boob size from the pill ?

Caitlin • Grad. Student. Avid foodie. Wine lover. Lucky. In Love.
When I was on birth control the first time, I became a D cup. 
When I quit the pill for a year, I went to a B cup. Now, I'm back in my old D size bras. Any one else have this beneficial yet weird side affect from the pill? 
I don't mind my boobs being bigger, but is this fluctuation good for my body when i decide to quit the pill later in the future ?