Week 3

2   Articles

During the third week of pregnancy, the rapidly developing blastocyst undergoes further transformation as it prepares for implantation in the uterus. The inner cell mass differentiates into two layers, with one layer forming the embryo and the other contributing to the placenta. Hormonal changes continue, with human chorionic gonadotropin (hCG) levels rising to support the pregnancy and confirm it through pregnancy tests.