3 week of pregnancy: the expectant mother can still only guess and hope that fertilization has occurred successfully.

Many women perceive possible early signs of pregnancy, such as fatigue, irritability, nausea, altered taste preferences bloating and breast tenderness, dragging pain in the abdomen, as signs of approaching menstruation. There are no visible signs of pregnancy in some of expectant mothers at this time. The only nuance, which may alert a woman it that all of these symptoms she feels a little bit earlier than usual, critical days are a little bit in a hurry.

Similar signals are explained by introducing the blastocyst into the uterine wall: its external cells divide, forming blood vessels, and get used to the mucosa, where they begin to grow rapidly, eventually forming the placenta.

Starting from the third week of pregnancy the hormones estrogen and progesterone are produced inthe organism of future mother very actively. As a result of their work, we can forget about ovulation and menstruation during pregnancy.