The reproductive system uses the hormones and (later on) to ""think ahead"". They guide the preparation of the uterus for its role in supporting pregnancy.

Progesterone, Oestrogen

Explanation:

Progesterone:- This hormone helps in establishing the placenta. It stimulates the growth of blood vessels that supply the womb and also inhibits the contraction of Uterus. It strengthens the pelvic wall muscles.

Oestrogen:- It helps in the growth of Uterus, maintains its lining and also helps in the fetal organs development. With the help of progesterone it helps in the breast growth and milk duct development. It also activates the other hormones involved in pregnancy