first trimester calendar.

First trimester of pregnancy; Fetal development; Ovulation; Uterus; Morning sickness; Embryo implantation; Pregnant women

The article presents the calendar of the stages of development of fetus inside the uterus on the first trimester of pregnancy. It relates the process of ovulation, fertilization of eggs and implantation of embryo on the first four weeks of the first trimester until the fetus grows to become 2 to 3 inches long on the twelfth week. It also notes the feelings and body changes of pregnant women during the stages of the development, such as including morning sickness.