HEALTH: FDA Stirs Contraception Debate With OK For ‘Natural’ Birth Control App. 75% of the time, it works every time!
On the other hand, I remember this: “Basic sex education teaches us that the so-called ‘pull-out’ method is an unreliable and risky method of contraception. But a new study suggests that, in terms of pregnancy prevention, withdrawal works just as well as condoms.”
Related thoughts here.