Jennifer Fitz has a fresh take on the "how-is-NFP-different-from-contraception" thing.
No no no. NFP is not contraception. It is not like contraception, it does not do what contraception does, it has nothing to do with contraception. Ask a happy contraceptor to use NFP, he’ll quickly confirm this for you.
NFP is a form of abstinence. It’s a method for not having sex.
I realize that doesn't make it sound very fun, but go read the whole thing.
Readers of mine who are not even Catholic may find it very bizarre that, among Catholics who are aware of and accept Church teaching against contraception, there is a substantial contingent who are deeply suspicious even of couples discerning that they ought to use NFP at all.
Yes, it's a fringe group. But Catholics-who-are-aware-of-and-accept-Church-teaching-against-contraception is already a fringe group. So the fringe group within the fringe group can seem fairly substantial.
And if you're firmly within the larger fringe (as in my position, which is that we can have interesting hypothetical discussions about "sufficiently serious reasons" all day, but when it comes to real couples in real marriages, it is their own damn business whether to abstain from sex today or not) it is exhausting to keep having a public debate over and over again about what is essentially a matter of private discernment. Nevertheless, I soldier on.
Anyway, I like Jennifer's take. Worth reading.