HYPOTHALAMUS: Gonadotropin-releasing hormone (GnRH) is released by the hypothalamus (at the base of the brain). GnRH is needed to begin the ovulatory cycle.  PITUITARY: GnRH is secreted into the pituitary gland (located right below the hypothalamus) where it stimulates the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). FSH and LH promote the development of the ovarian follicle that contains an egg.  

OVARY: FSH acts on the ovary to continue growth and development of the follicle. Within the follicle, FSH promotes the production of estrogen. Estrogen causes a mid-cycle surge in LH, which stimulates ovulation. The follicle ruptures and the oocyte (egg) is released.

ENDOMETRIUM: The remaining cells in the follicle transform into an endocrine tissue called the corpus luteum, which secretes progesterone to prepare the endometrium for implantation of an embryo if fertilization should occur. 
 
FALLOPIAN TUBES: These tubes extend from the upper part of the uterus and the ends (fimbriae) surround the ovaries. They pick up the released egg from the ovary. Fertilization occurs in the Fallopian tube that is in touch with the ovary that releases the egg. The fertilized egg then develops into an early embryo and is slowly transported into the uterus (within about four days).
 

UTERUS: Once in the uterus, the embryo implants into the wall of the uterus and development of the placenta and fetus begin. Development continues until birth.
 

CERVIX: Located at the bottom of the uterus, the cervix opens during labor to accomodate the birth of the baby.

If pregnancy occurs, the next ovulatory cycle will not begin until after the baby is born. If mom breastfeeds, the next cycle will usually be postponed even longer.