Phil and I knew that we would use Natural Family Planning (NFP) since before we were even engaged. We talked about having loads of children (I wanted twelve, and he was happy with a huge family) and knew that if we ever had serious reasons to space out those future children, we would turn to NFP to do so.
Once we were engaged, we began taking classes to learn how NFP works in all it's gritty detail (I still can't say the "m" word without throwing up a little) and I started charting my temperature about six months before we were married to get a good idea of my body's cycles. We learned the Sympto-Thermal Method, which includes charting your basal temperature each morning and also your body's natural signs of fertility. However, I mostly relied on the temperature readings to indicate what was going on, as I was not fully comfortable with taking and interpreting the other signs. Well, we used that method for one whole month of marriage before getting pregnant unexpectedly (but happily!) with John-Paul. Looking back, I can see that we were not reading the charts very well, but I can also thank God for that since it made us parents!
After his arrival, for some reason we went back to the dark ages and basically used the rhythm method where you don't chart but instead use the calendar to determine when you're fertile. This is not scientific at all, and doesn't normally work as women's cycles can vary from month to month. However we managed for a while only because we were ultra conservative and took no chances (or so we thought). Babies number 2 and 3 and 4 were conceived during this time. The second and third were "planned" (aren't they all planned by God?) and the fourth baby was another surprise.
After Maggie, we found out about the Creighton Model, which basically uses a woman's biomarkers (or bodily signs) to determine her cycles. By this point I was a lot more familiar with my signs and did not want to go back to temperature taking and we successfully used this method for almost four years until we tried for and got pregnant with the fifth baby. It was during this fifth pregnancy that I learned about the Marquette Model of NFP and we decided this "new" method was going to be our choice for after Alexander's birth.
So here we are, ten years of marriage, five children, and four methods of NFP later and we are very happy with the Marquette Method. What is this method of NFP you ask? Well, you purchase a Clearblue Easy Fertility Monitor and test strips (these are the cheapest I can find) and follow these directions if you are looking to postpone pregnancy. Although it is a more costly alternative (about $10 per month after the monitor is purchased) , it is a simple and easy no-nonsense approach to NFP. There are no signs to monitor, no temperatures to take and no charts to interpret (I do chart for historical purposes here). The monitor gives you a reading of Low, High or Peak so that you know exactly when you should abstain or try to conceive.
The only downside is that it's so precise that one could grow accustomed to using it without ever questioning one's motives for using NFP at all. I think through the early years of our marriage, using the other methods of NFP really required faith because we weren't ever 100% sure of what we were doing, and this allowed for more openness to unplanned babies. Now I feel that we are more certain of what's going on and have to work harder to make sure we don't have a contraceptive mentality while using NFP. Maybe I'm being scrupulous about it, but not following God's will for my family is the biggest fear I have. Anyways, I do know that feeling confident in whatever method of NFP you choose is a good thing, and I'm glad we have finally found it!