Yet we decided to try it anyway. While there was a mild financial incentive for doing so, the main motivator was what we had discovered about most of the types of birth control available. The largest concern was that most of the birth control methods available were actually forms of abortion, a practice which goes not just the teachings of the Church, but both of our personal sets of beliefs. While the manufacturers of these products claim that their birth control process has nothing to do with abortion, the truth is that many of them work by destroying fertilized eggs (the start of human life). Many of those that don't, such as the ones that keep a woman's eggs from releasing, cause long term problems with the woman's overall health and well-being.
Even the "safe" birth control products have significant side-effects. While there has been a movement against vaccines due to rises in autism and ADHD, few people have publicized a stronger correlation (no causation proven yet) between those conditions in children and their mothers' use of pharmaceutical contraception. Even the side-effects listed for these medications can be quite extreme. All of this for a product that is not a hundred percent reliable even when followed correctly. There is always a chance that an egg can get fertilized in the short release window and somehow survive to implant in the uterus (although this can often lead to birth defects). Pharmaceutical companies are interested in profits, not women's health.
Natural family planning, on the other hand, does not add pharmaceutical substances to a woman's body and thus avoids damaging the woman's body. As this method relies on women knowing and understanding their ovulation cycle, it is 100% effective when followed. It also helps a couple discuss the sexual activities more as men are now more invested, and interested, in the woman's cycle. It requires the couple to work together rather than just keep the entire burden on the woman.
In our case, it led to better sex. It turns out that one of the side effects of the type of birth control my wife had been using was a decreased libido, so we actually started having sex more often in a given cycle despite the smaller time frame. We also were more open with each other when talking about sex since we were working together. Now, this is not to say that everything has been perfect since we started using the system, but it certainly has been better.