The 3rd week of pregnancy is the 1st week of the embryo’s development: your last period was 3 weeks ago and 1 week ago you ovulated and conceived.
The fertilised egg slowly moves through the fallopian tube to the uterus. At the beginning it is only a fraction of a millimetre wide, but it constantly divides and develops rapidly. This small cluster of cells forms the blastocyst, which implants itself in the uterus at the end of the 3rd week of pregnancy. This may cause light bleeding. The blastocyst consists of inner and outer layers. The inner cells will develop to form the embryo, while the outer cells connect to the mother’s circulatory system and will become the placenta.
Your body will now produce lots of different hormones to regulate the processes involved in the pregnancy. These hormones are also responsible for the various signs of pregnancy, which each woman will experience differently. The most common symptoms experienced during pregnancy include nausea, sudden sensitivity to smell, the need to urinate more frequently, breast tenderness and excessive tiredness.