Six to eight weeks after birth a woman can go on birth control. Keep in mind that breastfeeding mothers should only take one type of hormonal birth control because the other types can go to the baby in the breast milk. The types that are allowed to breastfeeding mothers are:
"progestin-only pills, also known as mini-pills, Mirena, and Depo-Provera, and a hormonal intrauterine device (IUD) are for you. According to doctors, progestins cannot enter your breast milk, as they are too big, and do not affect your infant."