Here is a table comparing the sites of production of estrogen and progesterone in the menstrual cycle and in pregnancy: (Attached Photo)
In the menstrual cycle, estrogen is produced primarily by the developing follicles in the ovary. After ovulation, the remaining part of the follicle, called the corpus luteum, begins to produce progesterone to prepare the endometrium for implantation of a fertilized egg.
During pregnancy, both estrogen and progesterone are produced by the placenta, which is formed after implantation of the fertilized egg. The corpus luteum also continues to produce progesterone until the placenta takes over this role. These hormones play important roles in maintaining the pregnancy and preparing the uterus for childbirth.