These are quotes from article I red recently, written by Professor Janet Smith.The link to the whole article you can find on the bottom of page.

 The Church approves of what is called Natural Family Planning or NFP. NFP is not the old rhythm method. It has nothing to do with counting days. I’m going to be explaining NFP by reference to days and numbers, but that’s irrelevant really to what I’m saying here; any woman can use NFP no matter how irregular her cycles.

A woman is a relatively infertile creature. For a long time it has been said that a woman is born with all of the eggs that she is ever going to have. Now some researchers are saying women may produce more during their lifetime, but, whatever is the case, women have only a couple hundred thousand eggs, maybe at the most a million or so. Males, on the other hand, are unbelievably fertile: any male has four to five, six to seven million sperm in any ejaculate. So, comparatively speaking, women are incredibly infertile.

Women ripen and release only one egg a month. That egg lives in a woman’s body for only 24 hours. It can be fertilized for only 12 of those 24 hours. So there is only a 12-hour window every month when a woman can get pregnant. It’s more complicated than that, of course. At the beginning of a month a woman has a few days of bleeding. That’s because she didn’t conceive the month before. During the last cycle she built up an endometrium which was prepared to receive a new little fertilized ovum, a new little human being. If there’s no little human being, she sheds the endometrium. Then a woman has what are called dry days that can last for several days. There is no bleeding and there is no fertile mucus. Her body is resting from having bled for a couple days. She’s got to restore herself. At the same time her body is preparing for the next cycle of ovulation. She is starting to produce hormones that are going to cause her ovaries to ripen and release an egg and send it down the fallopian tube. As those hormones are preparing that egg for ripening and releasing, the woman is starting to produce a certain kind of fertile mucus that she can recognize in her system. It is present throughout the whole fertile phase. It disappears about two or three days after she’s ovulated.

If that fertile mucus appears on a Monday, but a woman doesn’t ovulate until Friday, she can get pregnant from any act of sexual intercourse she had between Monday and Friday because the fertile mucus helps preserve the sperm and carries it to meet the egg. If she has sexual intercourse on Monday, but not Tuesday, Wednesday, or Thursday and ovulates on Friday, she could get pregnant from the act of sexual intercourse that she had on Monday although it is only about a three percent chance. On the day that she ovulates she has about a 43-47 percent chance of getting pregnant. Twenty-four hours later the egg dies if it is not fertilized. The woman cannot get pregnant for the rest of the month. It’s absolutely impossible. It’s only during the fertile part of the month that a woman can get pregnant. She cannot possibly get pregnant during the first third of the month since there is no egg available. She cannot possibly get pregnant for the final third of the month because there’s no egg available. The egg has come and the egg has gone. At about the same time the fertile mucus dries up. So a woman knows that she has ovulated and she’s not going to ovulate again. Her temperature also goes up a bit and stays up for the rest of the month. So when a woman sees her temperature rise for a couple days in a row, she knows that she has ovulated, the egg has come and the egg has gone and she cannot get pregnant for the rest of the month. There’s also a change in her cervix that alerts her that she has entered the fertile days and exited the fertile days.

Ninety three percent of women can learn how to read their bodily signs with one month of observation. Ninety-three percent of women figure out right away when the fertile mucus is present. The other seven percent, however, have some trouble reading their signs of fertility. Some of these women have a problem because they are infertile. If a woman is infertile the signs of fertility are not going to show up. She is not going to have the mucus because she is not producing the hormones to help her ovulate. A very good way for a woman to determine whether she’s fertile or infertile is to use natural family planning. There may be other reasons for unreliable signs besides infertility. A woman, for instance, might be taking medication that dries up the mucus. She might have allergies that cause her to produce mucus during the infertile days. But almost every woman within 3 to 4 months of observing bodily signs can determine when she’s fertile and when she’s infertile.

  Effectiveness of Natural Family Planning

Natural family planning is every bit as effective as any form of contraception. Dr. R. E. J. Ryder published an article in the British Medical Journal in 1993 in which he reviewed studies done by world health organizations on natural family planning and concluded that pregnancy rates of couples using NFP have depended on the motivation of couples. He concluded:

Increasingly studies show that rates equivalent to those with other contraceptive methods are readily achieved in the developed and developing world. Indeed a study of 19,843 poor women in India had a pregnancy rate approaching zero. Natural planning family is cheap, efficient, without side effects and may be particularly acceptable to and efficacious among of people in areas of poverty.

Of the women studied, one third were Christian, one third were Muslim and one third were Hindu. Most of them were illiterate. Do you know who was teaching them? Mother Teresa’s nuns. Mother Teresa had all of her nuns learn how to teach natural family planning.

NFP costs nothing and is perfectly healthy. A fraction of the money, a fraction of the billions of dollars recommended by the UN for contraceptives could be used to teach women NFP and there would be billions left for health care, antibiotics, hygiene, making the water supply safe, etc.

Benefits of NFP

One benefit of natural family planning is that there are no bad physical side effects. One of the reasons that NFP marriages last longer is that women using NFP are not as irritable, prone to depression and gaining weight and to having a reduced sex life as are women on contraceptives. The non-contracepting woman is a healthier woman; she feels better. She is not taking all the drugs that mess with her system.

Secondly, using NFP requires mutual sacrifice. That is key. It takes two people to have sex. It takes two people to abstain. Not one or the other of the couple is bearing the contraceptive burden. In couples where natural family planning is used wives generally think their husbands are exceptional men. She thinks “I married myself an exceptional man. He doesn’t ask me or expect me to take all of these drugs into my body that are bad for me. He enjoys my company even when I’m not sexually available. He can control his sexual desires. He’s probably not masturbating and using pornography. I’ve got myself an exceptionally fine man.”

And when a man is married to a woman who thinks he’s exceptionally fine, he tends to think he’s exceptionally fine. It does good things for his self-esteem. We women can be very critical. When a wife thinks her husband is an incredibly wonderful man, that makes for an incredibly wonderful relationship. He respects his wife; she respects him.

NFP enhances communication between spouses and strengthens marriages. For some time I wondered how NFP enhances communication. I figured it out one day and some people now accuse me of hiding in their closets and listening to their conversations. I understand that about once a month, somewhere during that 7 to 10 day period of abstaining, a couple want to have sex, especially since she’s fertile and males and females are more attracted to each other when the female is fertile. So they have a conversation that usually begins with the question: “Why did we decide it wasn’t a good idea to have a child right now?” That’s a very important question because if the answer is that having a baby would be acceptable, the couple can go ahead and do what they want to do.

Now if a couple has a good reason for not having a baby right now, that can go a long way to dampening the sexual desire. Spouses have some pretty revealing conversations about the reasons. The wife might say, “if we have another child right now I’ll kill you.” That could lead her husband to remember that there is a sporting event on TV that he very much wants to watch.

Or she might say, “You said that you would do the dishes. You said that you would give the kids baths. You said that I would have time for shopping on Saturday. When was the last time that you did the dishes or gave the kids a bath or gave me any time on Saturdays?” And he may respond: “I forgot; I’m so sorry. I didn’t know. All right, I’m on duty.” Or she might say, “I have been tired with three kids under 5 but the baby is out of diapers now. If we had another one I could handle it.”

Or the husband might say to the wife, “The reason we’re not having more babies right now is because I just can’t imagine how I’m going to support the kids that I’ve already got. I am worried about paying for braces, tuition, and having to buy a bigger van. The way you spend money!! Your friend Jane wants a fence, you need a fence. Your friend Jane gets a new kitchen, you need a new kitchen. What’s a man supposed to do? And she might reply, “I really had no idea that you felt that way. I don’t need that kitchen. I don’t need a fence.” Or he might say, “I was worried about finances, but I have been getting raises along the way. My dad raised 4 or 5 children on next to nothing. If he could do it, I can do it. So, yes we can go ahead. If there’s another baby around here, we can handle it.”

That conversation takes place about once a month for couples who are using natural family planning. It makes them assess where they are in respect to these key questions: why are we having children and why are we not having children? Who’s carrying their weight around here? Who is not? That’s the kind of conversation that marriage counselors want every couple to have, touching base with each other. Natural family planning couples have that conversation.

Most people who use natural family planning have contracepted at one time. They know the difference between a contracepted relationship and an NFP one. Nearly all of them testify that their NFP relationship is definitely better than their contraceptive relationship was. When they were contracepting they rarely had conversations about having or not having babies. They decided they were not having a baby for another 3 or 4 or 5 years. They just get all involved in their own world and don’t talk about the mutual world they should inhabit.

NFP strengthens a couple’s relationship with God. Catholics who come to accept the Church’s teaching on contraception generally have a whole new respect for their church. It’s an incredible Church that has this teaching. The Church clearly isn’t trying to win a popularity contest. It teaches against contraception because this is God’s truth, not man’s truth. These are God’s laws, not man’s laws. Some of God’s laws are very peculiar to us. But when we live by them, when we love our enemies, for instance, we’re usually a lot better off than when we hate them. And it’s counterintuitive to think you ought to love your enemies. But if we live by that then we’ve got a better world. We thought contraception was going to be great, but maybe it’s not. My view is that if people stop using contraception, we will reduce the problems in society. Poverty will go down. Crime will go down. People will generally be happier and better off.

link to whole article: http://www.catholiceducation.org/articles/sexuality/se0002.html