The organism of the woman works as the perfect, debugged mechanism. In certain days the pregnancy probability increases, there are also periods when conception is impossible.
As there occurs pregnancy
Every month in an organism of the woman one ovum ripens. It develops in one of ovaries about 10-13 days, and then, within 24-48 hours, moves to the uterine tube conducting to a uterus. This process is called an ovulation. During an ovulation the organism is preparing for possible pregnancy, in a uterus the new mucous membrane is formed, special hormones are produced. The ovum remains in a uterine tube about one day. If during this period she unites to a spermatozoon, there will occur pregnancy. Otherwise the ovum perishes and after a while is removed from an organism together with blood and a mucous uterus - there come the periods. Thus, it is possible to become pregnant only in the certain time connected with an ovulation.
In what days it is possible to become pregnant
The number of days between the beginning of periods is called a menstrual cycle. The ovulation comes approximately in its middle. Duration of a menstrual cycle is individual for each woman therefore the ovulation needs to time independently. In a healthy organism the pregnancy can occur in the period of the ovulation and at most in 5 days prior to it. After an ovum exit from a uterine tube an opportunity to become pregnant is minimum, however the insignificant percent of probability remains. The remained time before monthly is considered days of natural protection.
The cycle of the woman depends on many factors, it can get off and change the duration. Therefore you should not refuse protection in days of natural contraception if you do not plan to bring the child.
How to define approach of an ovulation
The most widespread way is a measurement of basal temperature. It is necessary to carry out the procedure every day closer to the middle of a cycle. In day of an ovulation temperature decreases a little, and right after it - sharply increases.
Basal temperature is taken right after a dream, without getting up. For exact results you sleep not less than 5 hours and do not take alcohol.
It is also possible to be guided by subjective feelings. In the period of an ovulation can be ill a little a stomach and also sexual desire amplifies. The number of natural allocations increases and increases their viscosity. Recently tests for an ovulation became distributed - they are on sale in pharmacy and have the high level of reliability. But the most exact way is ultrasonic monitoring: within several days the doctor watches maturing of an ovum and can accurately define the ovulation moment.