(i) Lactational amenorrhea: Breastfeeding delays the resumption of normal ovarian cycles by disrupting the pattern of pulsatile release of GnRH from the hypothalamus due to production of prolactin and hence FSH and LH from the pituitary.
(ii) Progestin-only emergency contraceptive pills (morning after pills) are pills that contain levonorgestrel, a type of the hormone progestin researchers have found prevents pregnancy when taken in the few days after sex.
(iii) There are two main kinds of birth control pills — combination birth control pills, which contain estrogen and progestin.