Editing Menstruation (section)

=== Fertility aspects ===
Peak [[fertility]] (the time with the highest likelihood of pregnancy resulting from sexual intercourse) occurs during just a few days of the cycle: usually two days before and two days after the [[ovulation]] date.<ref>{{cite web|title=My Fertile Period | work = DuoFertility | publisher = Cambridge Temperature Concepts Limited |url=http://www.duofertility.com/en/my-body/my-cycle/my-fertile-period.html|url-status=dead|archive-url=https://web.archive.org/web/20081221225600/http://www.duofertility.com/en/my-body/my-cycle/my-fertile-period.html|archive-date=2008-12-21|access-date=2008-09-22}}</ref> This corresponds to the second and the beginning of the third week in a 28-day cycle. This [[fertile window]] varies from woman to woman, just as the ovulation date often varies from cycle to cycle for the same woman.<ref>{{cite journal | vauthors = Creinin MD, Keverline S, Meyn LA | title = How regular is regular? An analysis of menstrual cycle regularity | journal = Contraception | volume = 70 | issue = 4 | pages = 289–292 | date = October 2004 | pmid = 15451332 | doi = 10.1016/j.contraception.2004.04.012 }}</ref> A variety of methods have been developed to help individual women [[Fertility testing|estimate the relatively fertile]] and the relatively infertile days in the cycle; these systems are called [[fertility awareness]].{{medical citation needed|date=February 2021}}