What is "lunaception"

Lunaception is a practice that purports to enable a woman to know ahead of time when she will be fertile each month, based on practices stated by its advocate to be found in many non-urban cultures. It was named and described by Louise Lacey in her 1974 book Lunaception, and she maintains a website advocating the theory. The practice includes making a daily chart of temperature, condition of vagina, mood, and other observables, and sleeping in complete darkness except for three days each month. The name comes from the assertion by the author that most women's menstrual cycles usually become synchronized to one phase of the Moon during the three nights of sleeping with light. Lunaception has not received scientific testing.