Normal women of childbearing age ovaries monthly discharge a mature egg, after the ovum into the fallopian tube, generally can survive for 1-2 days, and the sperm produced by men is continuous. Typically maintained sperm in the female genital tract activity 2-3 days, and its ability to progesterone between 48 hours. Such as women having sex in a certain period of time before and after ovulation, may have become pregnant. This period is called "ovulation."

It is important to grasp this period, on the one hand allows those who missed the female ovulation sex life and lead to infertility in couples, to have the potential to greatly pregnancy; other contraceptive measures also allow those couples do not want to become pregnant, there is no under the circumstances, miss the "height" sex to prevent pregnancy.

Common projections "height" approach are:

Cervical mucus observation (to be done in hospital)

Basal body temperature measurement method

in the body after waking up after a long sleep time (usually in the morning), and has not carried out any activity prior to speak, the measured temperature, based on temperature. Normally, the basal body temperature of women of childbearing age, the first half of the menstrual lower, lower ovulation, ovulation may be sudden or slow the rise 0.3-0.6 deg.] C for 24 hours to several days.

Therefore, measurement of basal body temperature is best to start from the first day of menstruation, adhere to measure every day, and coordinate with paper records, in order to observe and analyze.

Date passing reckoning

think every ovulation should be about 14 days before menstruation, it will be five days before ovulation - five days after ovulation is called "ovulation." However, this method is not reliable, because most women menstruation is not so regular. By contrast the first two methods more reliable, but some trouble.