The concept of the third week of pregnancy is very conditional, because the egg has not been fertilized yet. Exactly during this period the process of conception may happen (if it does not happen in the past, the second week of pregnancy), followed by the migration of the fertilized egg of the fallopian tubes into the uterus, where the embryo is firmly fixed in the layer of the endometrium and active development of the fetus begins.

In the third week of pregnancy, the expectant mother cannot feel any changes in her body, while there are many important processes happening.