After the conception has taken place, intensive processes begin inside the expectant mother, which she most often does not know about. On the very first day, the fertilized egg divides and moves along the fallopian tube, where the conception took place, into the uterine cavity. This journey lasts about four days. It is no longer a set of individual cells that descends into the uterus, but a blastocyte - a formation in the form of a ball. It is embedded in the lining of the uterus. This is implantation. This happens 6-7 days after fertilization, and sometimes a woman feels implantation by slight pulling sensations in the lower abdomen.
The earliest symptom of pregnancy is sometimes the so-called implantation bleeding - a few drops of bloody or sanious discharge at the time of the introduction of blastocytes into the endometrium. This does not mean that it is time to run for the test or sign up for an ultrasound.
The test strips react to the formation of the so-called pregnancy hormone - hCG, and it is just beginning, the hormone level is below the control level of the sensitivity of the test strips. And on ultrasound, a blastocyte cannot be seen - its size is only 0.2 mm.
There is no placenta yet, the uterine mucosa "supplies" nutrition for the embryo. But from the very first day after attaching, the baby begins to produce hCG, this hormone gives the entire female body mass “mobilization” commands. The restructuring of all systems of the female body begins in order to create the most comfortable conditions for the further growth of the child.
Two weeks after conception, the child grows up to 1 mm, menstruation begins to be delayed, and during this period, pregnancy can already be determined with a high probability by the level of hCG in the blood (if a woman takes a blood test from a vein), test strips begin to “strip”. However, on ultrasound, the woman is still not happy with anything, pregnancy is not yet visible.
3 weeks after conception (this is the fifth obstetric week, which is counted from the first day of the last menstruation), the size of the baby reaches 4 mm. The neural tube is laid in him, and the formation of the placenta also begins. The embryo takes on an oval appearance - a fetal egg appears. Exactly 3 weeks after conception, the formation of the brain and spinal cord begins, and the heart begins to beat in the embryo.
It is a week after the start of the delay (this approximately corresponds to the 21st day of embryo development or a full 5 obstetric weeks) that the embryo can be seen for the first time using ultrasound diagnostics. However, this possibility depends on many factors.
• A woman should not have polyps and diseases of the uterine mucosa. If there are such pathologies, the doctor may confuse the fetal egg with a fragment of the polyp, and it will not be possible to confirm the pregnancy.
• The scanner must have a good resolution, it is possible to determine pregnancy at such a minimum period only with modern good equipment and, of course, with the help of an experienced and qualified doctor.