Explain why it makes sense that the levels of estrogen and progesterone are low in blood of a female during menstruation

During menstruation, the lining of the uterus is shed. Since one role of estrogen is to tell the body to grow the uterus and replace the lining of the uterus, and one role of p rogesterone is to instruct the uterine lining to stop growing so that it might develop and mature, it makes sense that these two hormones would be repressed during menstruation as these two outcomes would be undesirable at this time.