The four main hormones that influence ovulation are: FSH (follicle stimulating hormone), Estrogen, LH (luteinizing hormone) and Progesterone.

At the very beginning of the cycle, FSH (follicle-stimulating hormone) is the first hormone to act. It stimulates the maturation of the Graafian follicles which contain the egg cells. When at least one of the follicles reaches the right size, the body starts to prepare for ovulation and releases two hormones: estrogen and LH.

Estrogen appears first, and its increased level is responsible for the changes taking place in your body to prepare for ovulation, such as an increase in the amount of mucus and the creation of fertile cervical mucus (watery or eggwhite).

After the increase of estrogen, the level of LH also increases. Upon reaching its peak level, the LH stimulates the Graafian follicle to release the mature egg cell.

About one day after the release of the egg (ovulation), the third hormone, progesterone, begins to act. Simply put, whereas estrogen is the hormone reponsible for changes in mucus, progesterone is the temperature hormone. Progesterone increases the level of body temperature, which confirms the occurrence of ovulation. The higher temperature phase will last until the next menstruation.