The menstrual cycle is the regular natural change that occurs in the female reproductive system. In theovary, where oogenesis take place, each cycle can be divided into three phases consisting of thefollicular phase, ovulation and luteal phase. The menstrual cycle is controlled by hormones ofhypothalamus-pituitary-ovary axis. The figure shows alternations in body temperature and hormonalchanges during the menstrual cycle.