On average how long does it take to concive a baby after quitting the nuva ring?

1-12 months: You should return to fertility about a month after stopping it. That doesn't mean you will get pregnant right away, though. It is normal to try for up to a year to get pregnant even if there is nothing wrong with your fertility.

~20% per cycle: One may conceive the cycle right after discontinuation of the ring. Doing so would probably yield ~20% chance of conceiving each cycle (lower with advancing reproductive age), ~50% chance conceiving within 6 months, ~85% conceiving within one year. If not pregnant by then, recommend seek infertility evaluation.