Progesterone is a steroidal hormone that is present in embryogenesis, pregnancy, and the menstrual cycle. It controls regulates estrogen. Since estrogen is responsible for the proliferation of cells and in the thickening of the lining of your uterus, progesterone sees to it that it doesnâ€™t get to far. If you go not have enough progesterone in your body, then estrogen will increase in level. This results into hormonal imbalance.