And because we have less GnRH released, that means we'll have less of SSH and LH being produced. Now, it's the LH that is needed to maintain the corpus luteum. And if we have less LH being produced as a result of the negative feedback process, then that means the corpus luteum will begin to slowly deteriorate and eventually it will break down into the corpus albicans. Now, if the corpus luteum decreases its function, that means progesterone concentration will decrease and so will estrogen. And that's because it's the corpus luteum that releases those two hormones. And as we decrease the amount of progesterone and estrogen that means our endometrium will begin to break down, the blood vessels will begin to rupture, releasing blood.