"Natural Family Planning (NFP) is an umbrella term for certain methods used to achieve and avoid pregnancies. [not the Rhythm Method] These methods are based on observation of the naturally occurring signs and symptoms of the fertile and infertile phases of a woman's menstrual cycle. Couples using NFP to avoid pregnancy abstain from intercourse and genital contact during the fertile phase of the woman's cycle. No drugs, devices, or surgical procedures are used to avoid pregnancy. NFP reflects the dignity of the human person within the context of marriage and family life, promotes openness to life, and recognizes the value of the child. By respecting the love-giving and life-giving natures of marriage, NFP can enrich the bond between husband and wife."
United States Conference of Catholic Bishops
To learn about Natural Family Planning:
Couple to Couple League
Hartford Archdiocese Office of Family Life
Learn Natural Family Planning
Pope Paul VI's Encyclical, "Humanae Vitae"
Pope Benedict XVI's Encyclical, "Caritas in veritate"
From Pope John Paul II's Encyclical, "Evangelium vitae":
"It is frequently asserted that contraception, if made safe and available to all, is the most effective remedy against abortion. The Catholic Church is then accused of actually promoting abortion, because she obstinately continues to teach the moral unlawfulness of contraception. When looked at carefully, this objection is clearly unfounded. It may be that many people use contraception with a view to excluding the subsequent temptation of abortion. But the negative values inherent in the "contraceptive mentality"-which is very different from responsible parenthood, lived in respect for the full truth of the conjugal act-are such that they in fact strengthen this temptation when an unwanted life is conceived. Indeed, the pro- abortion culture is especially strong precisely where the Church's teaching on contraception is rejected. Certainly, from the moral point of view contraception and abortion arespecifically different evils: the former contradicts the full truth of the sexual act as the proper expression of conjugal love, while the latter destroys the life of a human being; the former is opposed to the virtue of chastity in marriage, the latter is opposed to the virtue of justice and directly violates the divine commandment "You shall not kill".
But despite their differences of nature and moral gravity, contraception and abortion are often closely connected, as fruits of the same tree. It is true that in many cases contraception and even abortion are practiced under the pressure of real- life difficulties, which nonetheless can never exonerate from striving to observe God's law fully. Still, in very many other instances such practices are rooted in a hedonistic mentality unwilling to accept responsibility in matters of sexuality, and they imply a self-centered concept of freedom, which regards procreation as an obstacle to personal fulfilment. The life which could result from a sexual encounter thus becomes an enemy to be avoided at all costs, and abortion becomes the only possible decisive response to failed contraception."
(Pope John Paul II, Evangelium Vitae, #13)