Step-by-step explanation:
Hey, there!!!
Let me explain you very simply,
We generally call the last stage of female's monthly cycle as secretory phase. This phase is also known as lutel phase because of existence of Corpus Luteum. In this phase, tge anterior lobe of pituitary gland secrets Lutenizing Hormone (LH) which eventually produces Corpus Luteum in empty Folicle. Then the Corpus Luteum consequently secrets Progesterone hormone. With the help of Progesterone hormone, the endometrial layer becomes thicker and secretary glands of endometrial layer secrets watery mucus for the protection of the endometrium. If the fertilization doesn't occur secretion of watery mucus is reduced and so does the Progesterone hormone. This recults in next female's monthly cycle.
Hope it helps...