If the intimate proximity occurred at once after the termination of periods, approach of pregnancy is improbable. But in some cases fertilization nevertheless is possible therefore you should not hope for a calendar method of contraception.
In what days it is possible to become pregnant
Throughout a menstrual cycle the ability of the woman to fertilization changes. It is known that approach of pregnancy is most probable in case the intimate proximity occurs during the favorable period.
Approximately in the middle of a cycle there is a maturing of an ovum, and it gets from an ovary into a uterus cavity. At this moment it is completely ready to fertilization. If the intimate proximity at the woman occurs in the period of an ovulation, its chances of safe conception are maximum.
It should be taken into account that spermatozoa keep the ability to fertilization within 3-5 days. If the sexual contact happened in 3-5 days prior to an ovulation, pregnancy can quite occur. Chances of conception and within 4-6 days after maturing of an ovum as throughout this time it is still ready to fertilization are high. The ovulation occurs approximately in 12-14 days before the following periods. It means that the very first week of a cycle is rather safe. At this time the ovum did not ripen yet therefore its fertilization is theoretically impossible.
In what cases it is possible to become pregnant in the first week after periods
Some women use a calendar method of calculation of an ovulation as a contraception method. However it is necessary to remember that this method is not rather reliable. It is quite possible to become pregnant at once after monthly if a menstrual cycle irregular. In this case to calculate an ovulation very difficult. For these purposes it is possible to take daily basal temperature or to acquire several special tests in pharmacy. At once after monthly it is possible to become pregnant if the cycle is very short. For example, if its duration is only 21 day, the ovum ripens practically at once after the termination of menstrual bleeding. Experts assure that throughout a cycle the maturing not of one, and at once 2 or even 3 ova is possible. If it occurs all several times in a year, it is considered norm. Maturing of several ova at different times is one of the reasons of approach of pregnancy within the first week after periods. The probability of approach of pregnancy at the very beginning of a cycle is influenced also by "survivability" of spermatozoa. At some men this indicator is at quite high level. It depends first of all on a condition of their health, a way of life and also specific features. If the viability of sperm remains for 5-7 days, and the menstrual cycle at the woman lasts only 21-25 days, she can quite become pregnant at once after monthly.