Don't count on having been on birth control for years to slow you from getting pregnant... a number of women I know, including myself, became pregnant the very first month after stopping the pill, despite having been on it for more years than we could count.

I totally see where you are coming from and like MP I have seen my cycling-goal enthusiasm wax and wane over the years. That's ok. Cycling just for fun, or for the pleasure of discovering new destinations, is great too.