Fertility Awareness Center
- Non-profit group providing information on the method and steps to learn fertility awareness from a non-religious perspective.
- http://www.fertaware.com/

Fertility Circle
- Fertility Circle we bring you online fertility charting, ovulation calendar and natural family planning. Whether trying to become pregnant or trying to avoid pregnancy, we are here to help you.
- http://www.fertilitycircle.com

Natural Fertility of New Zealand
- Teaches natural fertility awareness for couples trying to conceive or trying to avoid pregnancy.
- http://www.naturalfertility.co.nz

Natural Methods
- Emory University School of Medicine review of abstinence, fertility awareness, breastfeeding, outercourse, and withdrawal as methods of birth control or child spacing.
- http://www.gynob.emory.edu/familyplanning/contraception_natural.cfm

Billings Centre
- Presents the Billings method for planning for future conception, includes a list of instructors in Canada.
- http://www.billings-centre.ab.ca

Billings Ovulation Method Association
- Information about this method and access to instructors who assist couples achieve future conception.
- http://www.boma-usa.org

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.
- http://www.usmev.com.au/gender.htm

Fertility Wizard
- Fertility calculator gives daily estimates based on menstrual cycle.
- http://www.gleeson.us/fertility/

Hormonal Forecaster
- Charts fertility to avoid or achieve pregnancy. Also generate personal statistics, and forecast future moods and behaviors.
- http://www.hfc.itgo.com/

Web Womb
- Fertility indicator and pregnancy tests. Information on the Fertility Awareness Method. Product, contact information and charts.
- http://www.webwomb.com/

Family of the Americas
- Discusses natural family planning through the ovulation method.
- http://www.familyplanning.net/

Fondation SymptoTherm
- Swiss organization offering support and information on the Sympto-thermal method.
- http://www.symptotherm.ch/en/

Feminist Women's Health Center
- Fertility Awareness Method (FAM) for natural birth control.
- http://www.fwhc.org/birth-control/fam.htm

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.
- http://www.rho.org/html/cont-nfp.htm

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.
- http://www.pnfpn.org

Billings Life
- Covers the Billings Ovulation Method of natural family planning, research papers and teaching material, identifies teaching locations other countries.
- http://www.woomb.org/

Twin Cities Natural Family Planning Center
- Information on Ovulation Method, human fertility cycles, and other non-chemical approaches to family planning.
- http://www.tcnfp.org/

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.
- http://www.naomi.ie/