Due to the fact that the vast majority of obstetricians count pregnancy on obstetric terms, even the expectant mother is not sure that her egg is fertilized at the first week. Therefore common pregnancy symptoms are also absent: no nausea, discharge, odor intolerance and swelling of the breast is not felt.

Pregnancy test at the first week of pregnancy will also show a negative result, therefore the level of human chorionic gonadotropin (hCG) is not high. The hCG – is a hormone that a female body begins to develop just when the fertilized egg is implanted in the uterus.

HCG level rises every day of pregnancy, for example, by the fifth day it ranges from 25 to 50 mIU / ml., by 4-th week of pregnancy its level is already about 3,000 mIU / ml. and higher. Based on these data, only at 12-14 days after fertilization a pregnancy test may show a pale second strip.