It is also crucial to improve the pregnancy preparation rate by accurately calculating the ovulation date. 1. The ovulation date is calculated by counting down 14 days or subtracting 14 days from the first day of the next menstrual period. 2. Ovulation = 5 days before the day of ovulation + 4 days after the day of ovulation The survival time of the egg is 24 hours and the survival time of the sperm in the woman’s body is 2 to 3 days, however, the best time for the sperm and egg to conceive is even shorter, so having intercourse 1 to 2 days before and on the day of ovulation has the best chance of conception. There are several ways for women to accurately find their ovulation day: a. Calendar table speculation method Each female cycle is divided into menstrual period, follicular period (pre-safe period), ovulation period and luteal period (post-safe period). A woman’s ovulation day is usually about 14 days before her next menstrual period. 5 days before and 4 days after the ovulation day, together with the ovulation day, a total of 10 days is called the ovulation period. For example, if the current period comes on the 1st and the next period will come on the 29th, the ovulation day will be the 15th of this month and the ovulation period will be from the 10th to the 19th of this month. Second, the cervical mucus method Cervical mucus is present throughout the menstrual cycle and it has subtle cyclical changes. Just after menstruation, the mucus secretion also gradually increases and becomes thin and transparent, similar to egg white, reaching its peak just before ovulation. It can also be said that the day with the highest amount of mucus has the highest probability of ovulation. At this time, if you stick your finger deep into the vagina and dip it into the mucus flowing from the cervix, you can pull the mucus into thin threads up to 10 cm long without stopping. After ovulation, under the effect of progesterone, the mucus secretion is significantly reduced, thick and cloudy, poorly malleable, and easily broken when stretched. Women can do a little test in the shower, before intercourse, when changing clothes or going to the toilet, but it is more troublesome. Third, the middle pain method Some people have pain in the lower abdomen in the middle of two menstrual periods, which happens to be equivalent to the time before ovulation, called middle pain or ovulation pain. Some experts have investigated that 97% of the intermediate pains are felt before ovulation, therefore, if there is intermediate pain, it can be assumed that ovulation will occur within 24 hours. This method is probably the easiest and simplest way for some people. However, the disadvantage is that there are some people who do not have intermediate pain and cannot use this method. IV. Basal body temperature method A woman’s basal body temperature changes cyclically during her menstrual cycle. Under normal circumstances, a woman’s body temperature before ovulation is maintained at about 36.5 degrees, with fluctuations in the range of 0.1℃, while at the time of ovulation (ovulation day) the basal body temperature will rise rapidly by 0.3℃~0.5℃, and the high body temperature will be maintained for about 14 days. By plotting the basal body temperature curve with this pattern, the day of ovulation can be found accurately. Start measuring from the 1st day of menstruation (i.e. the day when menstrual blood comes in). Before going to bed on the first day, place the thermometer on your pillow ready in advance. Be sure to place the thermometer under your tongue and measure it early in the morning before you wake up without doing any activity, and the measured one will be called the basal body temperature. The 2-3 days before and after the rise of basal body temperature is the range of ovulation and easy to conceive, called the fertile period. If you master this rule, it can be a good guide to contraception and conception. V. Ultrasound method (vaginal ultrasound to detect ovulation) Currently, major hospitals in China use negative ultrasound to observe the size of the ovaries, determine the size of the follicles and presume when ovulation is. Ovulation detection using negative ultrasound is currently the most direct and accurate method. If you can combine it with basal body temperature chart, secretion viscosity test and mid-term pain method, you can basically determine the ovulation day very accurately, so your chances of conception will be greatly increased. This method of ovulation day test is more accurate, but it is more expensive and troublesome to take off work, count the days, register and a series of other things, so it is difficult to stick to the hospital to monitor. Six, ovulation test paper It is best to open the test on the 3rd day after the clean menstruation. You have to test every day! You can’t use the morning urine test! If you get two bars or the second bar is deeper than the first bar, you will ovulate within 24 to 48 hours, and there is a possibility of pregnancy from 3 days before ovulation (sperm waiting for egg) to 3 days after ovulation (egg waiting for sperm). If you get two bars, you can have intercourse on the day of ovulation, and then have intercourse again every other day.