The site of fertilization is usually in the uterine tube. Initial development of the embryo also takes place in the uterine tube. However, most development is intrauterine (within the uterus).
Timeline 0-8 weeks:
Embryo. During the first 8 weeks of development, the developing individual is called an embryo. The processes by which the embryo develops are studied in embryology.
Timeline 9 weeks:
Fetus. During the remainder of the intrauterine period, the developing individual is known as the fetus. During this latter period, the details of structure and function develop.
Timeline 10 weeks:
During intrauterine development, the embryo/ fetus is within the amniotic sac. Floating free in the amniotic fluid, it is connected to the placenta by the umbilical cord.
The placenta is the specific area of exchange between the maternal blood and the fetal blood. By this exchange, the fetus gets rid of waste materials and acquires food, oxygen, and other needed substances from the mother.