It should be clear what happens to the body of a woman during the menstrual cycle and then such questions will become clear by themselves.
Menstrual cycle lasts individually from twenty-one to thirty-five days. In different months, it can change its duration, and in significant limits.
The phases of the menstrual cycle
The ideal menstrual cycle has a duration of twenty-eight days, and in this period three phases are distinguished, of which the first is the maturation of the follicle in which the egg is contained. It ripens throughout the first half of the menstrual cycle, and this occurs under the influence of estrogen - the ovarian hormones. A normal average woman whose menstrual cycle is twenty-eight days, the duration of the first period, respectively, is fourteen to fifteen days.
The second phase is called ovulation. In this phase, a mature egg breaks this vial - the follicle and is in the abdominal cavity, from where it enters the fallopian tube to meet the sperm. The ovum lives for another 24 hours after ovulation, and ovulation itself occurs on the twenty-eight day menstrual cycle from the fifteenth to the sixteenth day. Often a woman feels that the egg leaves, because she has pains in the lower abdominal region from the ovary, in which the egg is ripe. This ripening usually occurs only in one of the ovaries.
In the third phase, the formation of the yellow body is the place of the burst follicle. It is a gland of internal secretion, producing progesterone, which is a female sex hormone. Progesterone performs important tasks, the main among which are the maximum increase in the volume of the mucous membrane of the uterine cavity for the introduction of a fertilized egg into it, and the prevention of the emergence of new follicles. This phase begins immediately after ovulation and lasts until the end of the menstrual cycle, and this period is from the seventeenth to the twenty-eighth days. In the event that a fertilized egg into the uterus has not implanted, at the end of the third phase the yellow body begins to decrease in size and stops its action. At the same time, the uterus loses its hormonal support, tears away, and expels the blood vessels. Here, menstruation begins and simultaneously with the onset of a new menstrual cycle.
Pregnancy during the period of
Can I get pregnant during menstruation? In some periods of the menstrual cycle it is impossible to conceive.
And, indeed, having studied carefully the menstrual cycle, it can be determined that starting from the second day after ovulation in the body of a woman there is no ovum, hence pregnancy is impossible. It is the time from the seventeenth to the twenty-eighth day with the twenty-eight-day menstrual cycle and is called the period of absolute sterility and it will not be possible to get pregnant during this period.
However, there is a period of relative sterility. It is in this first phase, when the follicle ripens. The egg is not ripe yet, but once it is ripe, and the sperm can maintain its vitality in the woman's body for up to a week. Therefore, he has a chance to wait until the egg appears in the fallopian tube. That's why with the duration of menstrual bleeding about a week, at the end of sex it loses its safety.
It is not easy to calculate the time for safe sex correctly.
Calculation of the ovulation calendar
To determine at what time of the menstrual cycle it is impossible to conceive a particular woman, it should be analyzed for at least six months, preferably - a year, and hormonal contraceptives should not be used. A notebook and a ball pen are bought, a special calendar is created, in which all critical days are celebrated. In the case of a marked irregularity of the menstrual cycle, the calculation will be very inaccurate, and then you will have to use other methods to prevent unwanted pregnancies.
When menstruation occurs regularly and temporary deviations are small, then the calculation has the right to be accepted. In this case, the shortest and longest menstrual cycles are selected and recorded during the study period. Further, from the short one subtract the number "18" and the result is the day of the beginning of the dangerous period. For example, if the shortest period is 24 days, we get: 24 - 18 = 6 that is, the sixth day of the menstrual cycle. Now subtract from the longest period (for example, 28 days) the number "11" is subtracted: 28-11 = 17 that is, the seventeenth day of the menstrual cycle.
From the calculations it follows that the probability of unwanted pregnancy is great from the sixth to the seventeenth day of the menstrual cycle.
During the period of pregnancy, nevertheless, may occur. with prolonged menstruation, and until ovulation remains less than seven days, then the sperm can well survive until the appearance of the egg. In addition, there is a possibility of incorrect calculations during the irregularity of the menstrual cycle.
The same can occur with sudden violations of the menstrual cycle, which can be triggered by various diseases or other effects on the woman's body, for example, stresses, physical stress, harmful environmental effects, and the like.