Good for you Serena! The pill without estrogen is the only pill recommended during breastfeeding, once started. Starting too soon is not advisable. After giving birth, in fact, the fall in circulating progesterone levels is indispensable for the start of lactation, and starting on a progestin pill too early may interfere with milk production. It can be taken by the nursing mother after the first 6 weeks of postpartum (or after the first 3 weeks, if you decide not to breastfeed).