The progesterone pill affects the pituitary gland and lowers the secretion of FSH (follicle stimulating hormone) and LH (luteinizing hormone). Due to low FSH and LH ovulation does not occur i.e., there is no secondary oocyte to be fertilized. Fertilization is the fusion of male gamete (sperm) to the ova. In human the fertilization takes place in fallopian tube.