Theoretically, the longest day for a woman to have streaky leukorrhea would be the day of ovulation. As the ovarian follicles mature, the amount of estrogen and progesterone secreted by the ovaries begins to increase, causing the uterus, cervix and vaginal discharge to gradually increase and become thinner and thinner, showing a stretched appearance. On the day of ovulation, because the secretion of estrogen and progesterone in the body reaches its peak, the amount of leukorrhea secretion is also the highest, and the phenomenon of lacrimation is the longest. Changes in the amount and nature of leukorrhea are not only influenced by estrogen and progesterone in the body, but also by the living environment, mood and sleep, as well as the health condition of the body, so you cannot rely entirely on the observation of leukorrhea changes to determine whether ovulation is occurring. Therefore, it is necessary to combine other tests, such as ovulation test paper and ultrasound, to determine whether ovulation is reliable.