Natural Family Planning
Natural Family Planning is an attempt to define which parts of the month a couple can enjoy intercourse with a low probability of conception, and which times are best to avoid.
Natural family planning requires far more knowledge, planning and discipline than other methods of birth control and it is seldom if ever as effective as an IUD or some of the hormonal methods of birth control.
So first and foremost, natural family planning should not be considered unless you are monogamous and very committed partners who have a total understanding of what's involved--and even then, it is anything but infallible. (A husband and wife I know well who are both very conscientious physicians and who have practiced NFP to the T recently had an unexpected third child.)
It would also be less than optimal to practice NFP when you are younger and your ovulation is not as consistent as it might eventually be.
There are two forms or styles of natural methods, the NFP or natural family planning and FAM or fertility awareness methods.
FAM encourages couples to use a backup method such as condoms or a diaphragm during unsafe periods, where NFP is more religiously based and anti-contraception.
Toni Weschler's Taking Charge of Your Fertility--10th edition is considered to be the bible of NFP. Also be sure to get the accompanying software for the book to help you do the best planning possible.
If you are trying NFP and end up having intercourse during a less-than-optimal time, the man should pull out and ejaculate on the side. This will offer you way more protection than doing nothing. However, some religious groups might consider this to be a form of masturbation, heaven forbid.
