Anovulatory cycle
While the normal menstrual cycle in the human typically lasts 4 weeks (28 days, range 24–35 days) and consists of a follicular phase, ovulation, and a luteal phase, followed by either menstruation or pregnancy, the anovulatory cycle has cycle
lengths of varying degrees. In many circumstances, menstrual intervals are prolonged exceeding 35 days leading to oligomenorrhea (cycle >35 – 180 days interval), or even longer, amenorrhea. In other cases, menstruation may be fairly regular (eumenorrhea), or more frequent (intervals < 21 days), or there may be a loss of menstrual pattern (menorrhagia, dysfunctional uterine bleeding).
Quintaglio Ascension Trilogy
The estrous cycle of female Quintaglios is 18 thousand days, and a female will hopefully mate 4 times in her lifetime every cycle, normally. There are some exceptions though, as Natova, and one of her daughter with Afsan, arose when 16 thousand days old. Also some females will often at the estrous cycle, thus having very low fertility. While male can mate at almost anytime, they have to wait for a chance, when a female is currently about to enter the cycle and accept the invitation. Females do not have to stick with one male every time, instead, they follow their instinct and choose the right spouse for the moment. Despite living on their own territory, the Quintaglios often have a long lasting friendship with the previous spouses, with the possibility of some forms of pair bonding.