Editing Calendar-based contraceptive methods (section)

==Terminology==
While the terms ''rhythm method'' and ''fertility awareness'' are not synonymous, some sources do treat them as such.<ref>{{cite web |title=Rhythm Method |publisher=Contraception.net |year=2008 |url=http://www.contraception.net/resource_centre/rhythm_method.asp |access-date=2008-05-18 |url-status=dead |archive-url=https://web.archive.org/web/20080512001456/http://www.contraception.net/resource_centre/rhythm_method.asp |archive-date=2008-05-12 }}</ref>  However, [[fertility awareness]] is usually used as a broad term that includes tracking [[basal body temperature]] and [[cervical mucus]] as well as cycle length. The [[World Health Organization]] considers the rhythm method to be a specific type of calendar-based method, and calendar-based methods to be only one form of fertility awareness.<ref name="who">{{cite web|title=Medical Eligibility Criteria for Contraceptive Use:Fertility awareness-based methods | version = Third edition |publisher=World Health Organization |year=2004 |url=https://www.who.int/reproductive-health/publications/mec/fab.html |access-date=2008-04-29 }}</ref>

More effective than calendar-based methods, systems of fertility awareness that track basal body temperature, cervical mucus, or both, are known as symptoms-based methods. Teachers of symptoms-based methods take care to distance their systems from the poor reputation of the rhythm method.<ref>{{cite web |last=Weschler |first=Toni |title=Fertility Myths |work=Ovusoft |publisher=Taking Charge of Your Fertility |url=http://www.ovusoft.com/library/myths.asp#19 |access-date=2008-04-29 |archive-url=https://web.archive.org/web/20080422205032/http://www.ovusoft.com/library/myths.asp#19 |archive-date = 2008-04-22}}</ref> Many consider the rhythm method to have been obsolete for at least 20 years,<ref name="tcoyf">{{cite book | first=Toni | last=Weschler | year=2002 | title=Taking Charge of Your Fertility | url=https://archive.org/details/takingchargeofyo00toni | url-access=registration |pages=[https://archive.org/details/takingchargeofyo00toni/page/3 3–4] |edition=Revised |publisher=HarperCollins |place=New York |isbn=0-06-093764-5 }}</ref> and some even exclude calendar-based methods from their definition of fertility awareness.<ref>{{cite web |last=Singer |first=Katie |title=What is Fertility Awareness? |work=The Garden of Fertility |year=2007 |url=http://www.gardenoffertility.com/fertilityawareness.shtml |access-date=2008-05-18}}</ref>

Some sources may treat the terms ''rhythm method'' and ''natural family planning'' as synonymous.<ref>{{cite web|title=Rhythm Method |work=Birth Control Health Center |publisher=WebMD |year=2005 |url=http://www.webmd.com/sex/birth-control/rhythm-method |access-date=2008-05-18}}</ref>  In the early 20th century, the calendar-based method known as the ''rhythm method'' was promoted by members of the [[Roman Catholic Church]] as the only morally acceptable form of [[family planning]]. Methods accepted by this church are referred to as [[natural family planning]] (NFP): so at one time, the term "the rhythm method" was synonymous with NFP. Today, NFP is an umbrella term that includes symptoms-based fertility awareness methods and the [[lactational amenorrhea method]] as well as calendar-based methods such as rhythm.<ref>{{cite web |title=Natural Family Planning |work=Institute for Reproductive Health, [[Georgetown University]] |year=2005 |url=http://www.irh.org/nfp.htm |archive-url=https://web.archive.org/web/20060208191517/http://irh.org/nfp.htm |url-status=dead |archive-date=2006-02-08 |access-date=2008-05-18 }}</ref> This overlap between uses of the terms "the rhythm method" and "natural family planning" may contribute to confusion.

The first day of bleeding is considered day one of the menstrual cycle.