Diagnosing pregnancy at the earliest possible date is quite difficult, since the first symptoms, which both a woman and a doctor can regard as an onset of pregnancy, are also possible with various pathologies. Disorders such as premenstrual syndrome, disruption of the endocrine organs, neuropsychiatric diseases, or an overdose of certain drugs are not excluded.
But if a happy moment has occurred, then the first signs of pregnancy, which confirm its presence, are laboratory and instrumental studies. Early signs of pregnancy are due to hormonal changes (the production of hCG and progesterone).
Of the laboratory methods confirming pregnancy, the determination of hCG in urine and blood serum is used. Determination of the level of hCG in the blood can be carried out 14-21 days after intercourse, when conception has already occurred, and the embryonic trophoblast begins to intensively synthesize hCG. An increase in the level of the hormone in the blood is determined in a special laboratory.