$\to$ In lactational amenorrhoea, due to high prolactin level, gonadotropin level decreases.
$\to$ Oral pills are either progestogens or progestogen-estrogen combinations used by the females.
$\to$ Emergency contraceptives includes the administration of progestogens or progestogen-estrogen combination or IUDs within 72 hour of coitus.
So, lactational amenorrhoea, oral pills and emergency contraceptives involve a role of hormone.