When to start progesterone birth control pill after birth?

Melissa
Hello everyone! I just had my baby two weeks ago and I am breastfeeding. Shortly after I had her, several of the recovery nurses told me when to start the progesterone only birth control pill. However, some said I should start it two weeks after I had her (today), while other nurses told me to wait til six weeks after I had her. The nurses that told me to wait til six weeks said that if I took it any sooner that my milk supply might mess up. I am so confused. None of the doctors there that I seen during my stay told me when to start it. Does anybody have advice or experience with this?