Should I Continue Birth Control Before Asymmetrical Breast Reduction?

I've had asymmetrical breasts since puberty. I was a large C (l) and a small, tuberous C (r).I took birth control and my left breast grew to a DD while my right stayed the same. After getting off the pill, the left breast became a D. I am trying the ring, but my left breast is turning into a DD. I plan on getting a one sided reduction - but should I remain on the ring and get surgery to correct it as it is now? Or should I take myself off? In short how will birth control affect the outcome?