Only those women who carefully plan pregnancy use special tests for definition of day of an ovulation and accurately know the menstrual cycle, can be sure of date of conception to within day.
Instruction
1. On the other hand, usually such accuracy is also not required. To understand in what about a day – plus or minus two – there came conception, it is enough to remember date of the last periods which came before pregnancy. Why quite so?
2. The menstrual cycle of the woman usually lasts about 28 days and consists of two equal phases lasting 14 days. During the first phase of each cycle the organism of the woman is preparing for pregnancy: under the influence of certain hormones the inside layer of a uterus (where the impregnated ovum will be attached if fertilization happens in this cycle) is thickened, in an ovary the follicle is formed (a cavity in which the ovum develops before leaving and moving to a fallopiyeva a pipe). An ovum exit comes from an ovary in the middle of a cycle, usually for the 14th day from the first day of periods. The ovum, carrying the movement of the large fibers located on edge of a fallopian pipe drags on in it and moves towards a uterus by means of small pipe fibers. In a pipe usually there is also a meeting of an ovum and a spermatozoon, fertilization and the subsequent movement of already fetal egg in a uterus cavity, for attachment to its bottom and development of full pregnancy.
3. If fertilization did not happen, then there comes the second phase of a menstrual cycle – other group of hormones which prepares an organism for peeling of excess fabrics in a uterus is activated. After that, for the 28th day of a cycle there come the periods which also are rejection of the fabrics which were not necessary for implantation of fetal egg.
4. Thus, in the most probable afternoon for conception the 14th day of a menstrual cycle, plus or minus two days is. Therefore, having added two weeks by first day of the periods, last before pregnancy, you will be able to define day of conception quite precisely.