Ovulation because many factors affect a possible ahead of time or a few days later, the rhythm is divided into absolute and relative and absolute rhythm refers to the date of ovulation, even if there are changes in the days of absolute security. As a general before and after the date of ovulation will not change more than 3 days, the period (assumed to be 3 days) before and after a week should be absolutely safe, and away from the more recent period of time the more secure. Which is absolutely safe period of a few days? Female rhythm, which is a few days? 

Rhythm related to women have calculated that, from the period of ovulation Laichao the next 14 days before the date of the first 5 days and 4 days, but according to the specific circumstances of each individual, the possibility of a ovulation or two ahead of ovulation. 

Female rhythm and rhythm is divided into before ovulation and after ovulation rhythm. From that day to clean ovulatory menstrual period begins the day before the date that the safe period before ovulation. Ovulation from the period after the end of the first day of the next menstrual Laichao the day before for the safe period after ovulation. After ovulation rhythm than the more secure the safe period before ovulation. This is because some women are sometimes affected by environmental changes and mood swings and so on so that the effects of ovulation in advance so that the safe period before ovulation will be shortened, and was not aware of their own, so that the safe period before ovulation is not a big safety. Ovarian cycle by a month after another row of two eggs is extremely small, that is, after ovulation until the next menstrual period before Laichao time normally does not happen again for the second time of ovulation, so after ovulation rhythm on the relatively safe.