Conscious contraception is an attitude that women are responsible for themselves and their offspring. Choosing safe period contraception at least shows that we all have some knowledge of physiology and know that in vitro ejaculation, cola to kill sperm and other messy and stupid methods are not reliable. But! The name of the safety period contraception is really too unscientific, the failure rate is also quite high, all day to calculate the calculation, and finally or accidental pregnancy, a moment to feel cheated is not it? What is the safety period, not at all reliable! A. What is the safe period Generally speaking, healthy women will ovulate regularly every month, a woman with a menstrual cycle of 28 days, ovulation day is roughly 14 days before the onset of menstruation. The five days before and four days after the day of ovulation are called the ovulation period. After menstruation and ovulation, the remaining days are the famous safe period. The safe period method of contraception is established on the basis that there are some differences in a woman’s body between the ovulatory and non-ovulatory periods. Based on these differences, pregnancy can be avoided by judging the ovulation period and avoiding it, where the egg and sperm have no way to meet. However, the first three and then four, the first seven and then eight and so on, are too simple and crude, and not scientific. There are many reasons why the “safe period” is not safe. 1. Although women ovulate at the middle of their menstrual cycle, the outside environment, temperature, emotions, health conditions and other factors can make the ovulation time earlier or later. Some women can also experience “extra ovulation” when stimulated by sexual intercourse, producing unwanted “fruit”. 2, menstrual intercourse generally does not lead to pregnancy, but there is the possibility of accidental ovulation during menstruation, and menstrual intercourse can easily cause infection, which is harmful but not beneficial. 3, if a woman in menopausal age, when there is a small amount of vaginal bleeding, should only have intercourse on the fourth day after the bleeding stops, because this bleeding may be caused by an ovulation; 4, if you are changing from oral contraceptives to physiological contraception, then the first few months after stopping the pill may be additional ovulation or irregular menstruation, so these months should be as far as possible not to use safe period contraception. 5, many diseases can change women’s ovulation time, such as endocrine disease, kidney disease, etc.. If during this period with the “safe period” contraception, can often lead to contraceptive failure. Third, in the end how to contraception is the most reliable research found that the annual failure rate of the safety period contraception reached a staggering 25% or more. Therefore, the so-called “safe period” is actually not absolutely safe. Research data shows that the contraceptive efficiency of short-acting oral contraceptives is greater than 99%, while the correct use of condoms is about 98% of the contraceptive efficiency, women’s friends for their own health, please choose the right way to contraception, away from the safe period contraception.