Caspar has helpfully pointed out that that the proposed order of discussion found in Beginnings is incomplete. So, a point #4 has been added to that post. He also points out that in many senses this discussion has the cart before the horse. Systematically, starting at the new point #4 would make more sense in that if #4 were demonstrated successfully then there would be no need for particular discussions on things such as 'The Pill' and NFP. In many regards he is correct.
Nevertheless, I am going to suggest that we maintain the current course of discussion. Why? Because I believe it follows the progression in thoughts/beliefs/and practice that many of us have been on. It is the story of the journey that many Christian marriages have embarked upon in recent years. However, do not be mistaken, this is not to suggest in good post-modern Oprah-esque terms that my journey is normative for me, your journey is normative for you, and never the twain shall meet. The results of such endeavors are usually, "Well I think..." "That's great for you, but I think..."
Rather, our individual experiences should lead us to ask questions about life together in community, as the Lord's body, under Christ Jesus who is the head of His Church. Ultimately, and primarily we are interested in what the Lord has to say about the topic, and what the Church, therefore, has been given to believe, teach, and confess.