Back in the 20s of the 20th century, gynecologists Japanese Ogini and Austrian Knaus developed a calendar method of pregnancy protection, based on calculating the approximate date of ovulation and the corresponding abstinence from sexual intercourse on the days that are most favorable for conception. Ovulation is the moment when an egg, already matured and ready for fertilization, leaves the follicle. The observant woman always monitors in her body the symptoms and signs that accompany the ovulation process, although they are subjective, but when compared a couple of times with the exact methods that determine ovulation, the woman will be able to very successfully navigate with their help. It should be noted that as a method that protects against unwanted pregnancy, the method that determines ovulation is not suitable for protection.
Therefore, a more perfect calendar method of pregnancy protection was developed, called the symptothermal method, which, in addition to calculating the date of ovulation, takes into account, among other things, the physiological condition of the woman and is based on observations and calculations. Thanks to minimal intervention in the natural processes of the female body, this calendar for calculating ovulation, by the way, has become the only method approved by the Roman Catholic Church. Its essence is that the rate of ovulation passage is 14 days before the end of the cycle and does not depend on its duration.
By making notes in the calendar about the dates of the onset of menstruation and analyzing four to six cycles, the estimated dates of ovulation during such cycles are determined using a countdown of 14 days from the end date. If the menstrual cycle is 28 days, then with it ovulation falls on the 14th. A cycle of 26 days has ovulation, respectively, on the 12th day. If the cycle is 32 days, then ovulation occurs on day 18. Thus, counting 14 days from the beginning of the shortest or longest cycles, we find out the time interval in which the ovulation of a woman should approximately be for this period.
For a more visual understanding, such an ovulation table will serve. Suppose 6 regular cycles over the last period of time had a duration of 26, 28, 26, 29, 27, 26, and 29 days. For example, a cycle of 29 days. We calculate: 29-14 = 15. It turns out that ovulation is expected to occur on day 15. Accordingly, 26-14 = 12, this is the shortest cycle, ovulation time, respectively, falls on day 12. Based on this, this woman can expect ovulation in the period from 12 to 15 days of the cycle.
It is recommended that each woman keep her menstrual calendar and ovulation calculation calendar. It must be remembered that during the interval from 12 to 15 days - the time is still not quite a fertile period. Since before and after ovulation there are days that are quite favorable for conception. Therefore, women, having information, should take into account that the calendar method of pregnancy protection - especially unwanted - is very unreliable; it is recommended to use it only for approximate calculations of ovulation dates in combination with other, more accurate methods.
So why is the calendar pregnancy prevention method unreliable? The explanations are very simple. Ovulation does not always occur 14 days before the end of the cycle. The phase from ovulation to the onset of menstruation can have a duration of 12-16 days and fluctuate in such a framework in the same woman. In addition, quite often there are failures in the hormonal system due to various stresses, travels, climate changes. All these reasons affect the length of the cycle and its changes, unexpected shifts are possible, both a delay in menstruation and its premature onset.
Dear women, consider the information received and use it wisely!