Confusion over this is understandable, because health care professionals don't all agree about when breastfeeding women should start taking progestin-only pills (POP), or the "mini-pill." According to the American Congress of Obstetricians and Gynecologists (ACOG), you can start using progestin-only birth control pills immediately after childbirth. If you choose a birth control pill that contains estrogen, you should wait until you've established breastfeeding for at least one month. Keep in mind a lactating woman whose baby's sole nutrition is from breast milk won't ovulate in those first six weeks. Many women discontinue full breastfeeding within the first six weeks, which means they can ovulate before six weeks postpartum. Because many women don't return to their health care professional at this time, they wouldn't be able to get a prescription for birth control when they need it.