i've heard of that , but my periods are bad enough though, which was why i didn't do that.i know that it doesn't always work for people, but what my husband and i've always done which has worked is the pull out method.the only time i got pregnant, was when he didn't after my first son was 2 1/2 b/c i wanted another baby. and before i got pregnant the first time, he never pulled out for over a yr. i guess once you have a baby, it's easier to get pregnant again.