If an egg is fertilized and the embryo implants itself in the uterus, the ovaries will stop producing new eggs. Explain how the ovaries are signaled to stop egg production.

Six to 10 days after fertilization, the embryo attaches, or implants, itself into the lining of the uterus. During the next week or so, the embryo receives its nourishment and oxygen from the cells that make up the lining of the uterus. The two layers of cells become more pronounced.