Commonly, the female ovulation is about 14 days before the next menstruation. On the safe side, 5 days before ovulation and 4 days after ovulation as well as the ovulation day are included as ovulatory period, and other period of menstrual cycle can be called safe period.

Many women think that the days before and after menstruation are relatively safe. In fact, calculating the safe period to achieve contraceptive effect may be only suitable for fixed sexual partners or women with regular menstrual period. When calculating the safe period, the couple can not take the day of last menstruation as computational standard, and they also can not completely believe that a-week-before-and-after menstruation is absolutely safe period.

In fact, there are many factors that lead to insecurity during the safe period. Ovulation is affected not only by hormone, but also by changes of brain hypothalamus, body fat and nervous system. Accurately calculating ovulation is a rather difficult task. The success rate of using safe contraception period is between 65% and 95%. The highest efficiency can be achieved only when very accurate calculations are made. And during sexual intercourse, the couple should keep personal hygiene, to avoid inflammation. If getting infected, the patient should be treated with medication in time, such as Fuyan Pill.

Calculation of safe period

Generally speaking, the safe period features two stages in the whole menstrual cycle, one is before ovulation and the other one is after ovulation. A woman ovulates on the 14th day before her next period, and since the egg can survive for two to three days, the range can be extended to five days earlier and four days later.

It should be noted that when the sperm enters the woman's body, it can remain active for three days. So to be safe, the ovulatory period can b expanded again, eight days earlier. That is to say, 8 days before ovulation and 4 days after ovulation, total 13 days can be called ovulatory period.

Safe period calculation formula

Apart from ovulatory period and menstrual period, the rest of the days can be called safe period. Take a 28-day menstrual cycle as an example and make a brief explanation.

With the arrival of menstruation, the woman begins to enter the menstrual period of about 5 days on October 1. Based on her menstrual cycle of 28 days, it can be calculated that the menstruation will come again on October 29. So the date of ovulation is on October 15. According to the above inference, the ovulatory period of this woman is from October 7 to October 19, while the rest of the days can be safe period.

Author's Bio: 

For more information, please feel free to refer to for details and knowledge.