Klossg, the good grief was because - some women HAVE conceived seven days after intercourse.
NFP (or in earlier days, Fertility Awareness) has been highly effective for us - no unintended pregnancies, seven intended pregnancies, five of them on the first try and the other two within a few months. Only four living children however, two lost to miscarriage and one to preeclampsia.
I am a NFP convert on moral grounds, or maybe only obedient to the Church grounds, but it frustrates me to hear proponents going on about monthly honeymoons and it bringing couples closer - I never found that to be so - the reverse rather, and even more so now that pregnancy has a high chance of being life-threatening to me and any child I conceive.
Do it without a net is fine when oops brings the the blessing of a new baby - it's no fun at all when there's death below.
Mrs VS