| Billings Centre: Presents the Billings method for planning for future conception, includes a list of instructors in Canada. |
| Billings Life: Covers the Billings Ovulation Method of natural family planning, research papers and teaching material, identifies teaching locations other countries. |
| Billings Ovulation Method Association: Information about this method and access to instructors who assist couples achieve future conception. |
| Family of the Americas: Discusses natural family planning through the ovulation method. |
| Feminist Women's Health Center: Fertility Awareness Method (FAM) for natural birth control. |
| Fertility Awareness Center: Non-profit group offering workshops and private consultations in Manhattean, New York. Offers resources, contact and method information. |
| Fertility Friend: Assistance and information for conceiving naturally. |
| Fertility Wizard: Fertility calculator gives daily estimates based on menstrual cycle. |
| Fondation SymptoTherm: Swiss organization offering support and information on the Sympto-thermal method. |
| Hormonal Forecaster: Charts fertility to avoid or achieve pregnancy. Also generate personal statistics, and forecast future moods and behaviors. |
| National Association of the Ovulation Method of Ireland: Helps women learn how to manage their own fertility through monitoring body changes. Includes details of the Billings method of self-examination. |
| Natural Conception Control: The Dr. Eugen Jonas method. Provides details on how to use observations of natural cycles to accomplish contraception or to select a future baby's gender. |
| Natural Family Planning: Brief fact sheet outlines the advantages and limitations of natural family planning, also called periodic abstinence, which requires users to practice abstinence during the fertile period of a woman's menstrual cycle. |
| Natural Fertility of New Zealand: Teaches natural fertility awareness for couples trying to conceive or trying to avoid pregnancy. |
| Natural Methods: Emory University School of Medicine review of abstinence, fertility awareness, breastfeeding, outercourse, and withdrawal as methods of birth control or child spacing. |
| Ovulation Calendar: Calculates fertility period using actual dates while considering length of cycle, provides a printable version to share with physician. |
| Philadelphia Natural Family Planning Network: Information on teaching providers in the area, with dates and locations of classes. Also information on this form of birth control, who can use it and how to learn it. |
| The NFP Files: Collection of FAQs, articles, links, resources, and organizations that explain natural family planning as an alternative to contraception, sterilization and abortifacients. |
| Twin Cities Natural Family Planning Center: Information on Ovulation Method, human fertility cycles, and other non-chemical approaches to family planning. |
| Web Womb: Fertility indicator and pregnancy tests. Information on the Fertility Awareness Method. Product, contact information and charts. |
Classical
