They urge people to do so because they do get people who are pregnant again at their 6 weeks pp checkup. Either because people aren't educated enough to know how they gave birth to their little one in the first place (this seriously happens!!) or they weren't aware that EBF isn't good enough of a birth control on it's own. Condoms aren't even discussed which should be because there is a greater risk of infection of the womb so quickly after giving birth. The cerazette is a breast feeding pill, so it will give that protection if you want to use the contraceptive pill during breastfeeding. With formula feeding is does not matter which form of birthcontrol you wish. It's entirely up to yourself. It can take a week up to a full cycle before the protection of your contraceptive kicks in, so it's best to discuss with your nurse what option is best for you. But until 6 weeks I would like to recommend condoms over anything else.