They say it doesn't matter if you only have one shot, or 100 shots. It is a very powerful bc. I heard of people who got pregnant right away, and others who took over a year or longer to conceive. it depends on your body. My advice is to never goo back on the shot. I was on it for 3yrs just got off this oct. Luckily I got my period 2 weeks later and have gotten a period every month since Iv been off. Never got a period the whole 3 yrs, soo hope this is a good sign. They say some people don't even get a period after a whole yr of stopping. wish you the best of luck, and if you are trying to conceive, and do want kids in your future, dont go back on it. :)