You stated: “I’ve never met a childree by choice couple who used NFP.”
You won’t because people who use NFP tend to have more ambulant attitudes toward pregnancy. This is true in academic studies done on NFP and true in reality for two reasons. 1. NFP has a negative reputation. Because the method is considered not effective enough, people considering their options are told only to use the method if they’re ok with getting pregnant. 2. The vast majority of people who use NFP are Catholic. Catholicism teaches that matrimonial consent requires the consent to have children. As such, a such a couple who intends to enter a deliberately childfree marriage is failing to give matrimonial consent. IOW, it not morally permissible for couples to deliberately be childfree.
In fact, there is the debate over the contraceptive mentality and the moral criteria for using periodic abstinence. Angela Bonilla pointed out this problem in “Humanae Vitae: Grave motives to use a Good Translation”, where she points out how one translation of Humanae Vitae has led to the American Catholic landscape to pressure young couples into having large families or to feel a sense of guilt over using NFP.
“This opinion pervades the American Catholic landscape and imposes, for some, a great burden. The message that many Catholics receive about the legitimate use of periodic abstinence is that they must have “grave motives” to use it. Even the term “serious reasons,” which is sometimes used instead of “grave motives,” communicates the same negative, but uncertain, meaning. In response to this, some Catholics never practice periodic abstinence no matter what the circumstances, while some silently agonize with guilt and uncertainty when they do use it and feel pressure to conceive before their youngest child turns two. Some ignore the Church’s teaching entirely because it seems unreasonable, while, at the other extreme, many reproach themselves (or worse, others) for “not trusting God enough” when they do use periodic abstinence.”
“given that your methods described rely on one’s perception of ovulation as accurate and given what we see on the wedding bee forums from people who really are not sure when they are ovulating even though they chart every day, watch CM etc, how can a regular joe rely on NFP? You’d basically have to be close to abstinent, right? At least until you were confident you knew when you are ovulating.”
Its not so much knowing when you’re ovulating, as it is knowing when you’re fertile. Ovulation happens once per cycle. The ovum has to be fertilized within a 1 day. The reason NFP typically requires couples to abstain from sex for about a week is because fertile mucus (mucus the woman’s body produces as she nears ovulation) increases the lifespan of sperm. On average, the lifespan is increased to about 3 days, but the sperm can live inside the women for up to 5.
On non-fertile days, the type of mucus present in a woman’s cervix is too thick to pass down to her vulva (as such she experiences dry days) and it acts as a natural barrier to sperm. More on the types of mucus here.
In addition, the cervix of the woman opens wider during the fertile period while it closes leaving only a small opening during the non-fertile period. See photo of cervix here during both periods of fertility.
A basic/healthy pattern of fertility looks like this (note that the hormone graph shown below is not a normal part of the Creighton chart) The green days (what my husband call “go days”) are dry/infertile days. Fertile mucus is not observed. The red days are bleeding and the baby days are days of fertility. It should also be noticed that the white baby’s indicate fertile mucus, while the additional light green baby are the three days after the Peak fertility day that we abstain during if we wish to avoid pregnancy. Ovulation occurs sometime between P and 3, but we don’t know what the P day is until the day after.
In this cycle, the couple has a 10 day mucus cycle that they need to abstain from if they want to achieve the method effectiveness of the method. Since sperm only survives about 3 days and at longest 5 days, if this woman had sex on day 14 (first day of mucus), she probably won’t end up pregnant. But she still abstained from sex because she did not know how long her mucus cycle was going to be. For all she knew, she could ovulate the next day, the day after, etc.
When a woman’s chart doesn’t look remotely like this, this is the result of a health issue. Take these examples for instance.
Where things go crazy, is when women suffer with PCOS. Their charts tend to involve constant mucus throughout their cycles, looking like this.
Oddly enough, though it looks like the woman is super fertile, women with PCOS tend to struggle with infertility, but I do have friends with PCOS who have had no difficulty getting pregnant. And in those cases, they do tend to feel like NFP is a shot in the dark.
Now, PCOS has its own health risks in addition to difficulties in conceiving a child. It increases the risk of endometrial hyperplasia and cancer of the endometrium (uterine lining), diabetes, high blood pressure, etc.
Thus, while I’d recommend trying to find a physician trained in naprotechnology and really researching treatment options, it is morally permissible to be on the the same prescriptive used for its contraceptive purposes to treat something like PCOS.