From the beginning of menstruation, women ovulate about 400 mature eggs during their lifetime. In general, the ovaries ovulate once a month with one mature egg each time, but occasionally two to three eggs are ovulated at a time. Both ovaries alternate, but one ovary may ovulate back-to-back. If you do not conceive after ovulation, you will have your period half a month later. If you know the approximate date of ovulation, you will have a good idea of the date of conception or contraception, and you can control yourself. Ovulation usually occurs about 14 days before the next menstrual period, not on the 14th day of the current period. Therefore, you can roughly estimate your ovulation date based on the number of days of your usual menstrual cycle. For example, if a woman has a period once every 28 days, she will ovulate around 14 days; if she has a period once every 45 days, she will ovulate about a month after her menstrual cycle. Occasionally, women who are not yet menstruating, or who are not ovulating at all, become pregnant after having intercourse once. This may be due to sexual excitement stimulating the cerebral cortex, causing early ovulation or extra ovulation by the ovaries. During ovulation, the mature egg is expelled from the surface of the ovary to break through the follicle that wraps a membrane around the surface of the egg. When the egg is expelled, a small amount of fluid from the follicle flows into the lowest part of the pelvis; sometimes there is also a small amount of bleeding from the ovary where the egg is expelled. As a result, some women may feel a mild downward sensation in the anus and may also feel mild pain in one side of the lower abdomen. If you pay close attention, the same symptoms will appear on the other side of the lower abdomen the following month, and these pains will disappear after a few hours. Since the ovaries not only have the function of ovulation, but also control the secretion of female endocrine hormones, the fluctuation of estrogen secretion in the body before and after ovulation can cause a small amount of uterine bleeding, called ovulatory bleeding. This is another sign of ovulation, which some women may mistake for menstrual irregularities. In addition, the secretion of luteinizing hormone after ovulation causes the body temperature to rise slightly after ovulation. If you can insist on measuring the basal body temperature every morning, you will be able to find out your ovulation date based on the change from low to slightly elevated body temperature. Some women do not test their basal body temperature, but in the half month after ovulation, especially in the afternoon every day, they feel a slight fever, and when they have their period, they no longer have a fever. Many women experience breast swelling or nipple pain during ovulation, and sometimes it is simply impossible to touch the nipple, and the breast manifestations may continue until the eve of the next menstrual period. The last sign of ovulation, and the most obvious sign that women feel when they ovulate, is the change in vaginal discharge. During the first half of the menstrual cycle, the vaginal discharge is small, sticky and opaque; as ovulation approaches, the vaginal discharge gradually increases and becomes thin and milky; during ovulation, the amount of discharge increases significantly and becomes watery and clear, and the woman feels that her pubic area is moist and slippery, and when she wipes it with hand towels, there are egg-white-like streaks of mucus. This vaginal discharge lasts 2 to 3 days and is the most fertile time for women. The changes in vaginal discharge during the menstrual cycle and the fertile period are listed in Table 1. In conclusion, these changes during ovulation are present in every sexually mature woman. However, some of the symptoms are obvious and some are not and require careful attention to feel them. Along with the onset of ovulation, women also tend to experience a demand for sex. If one can master having intercourse during ovulation, then the chances of successful conception are sure to be greatly increased.