Sara Fox Peterson wrote a very informative article about NFP for Catholic Mom: Five Things I Wish You Knew. I especially like this paragraph:
NFP can be a tremendous blessing for a couple who must avoid pregnancy, but it is also a privation and most couples who seriously use NFP to avoid pregnancy for any length of time will feel this. God does faithfully supply the graces necessary to cooperate with Him and NFP is not impossibly burdensome when it is truly necessary, but it usually isn’t fun or effortless either. NFP is not an easy way out of the struggles and sacrifices of bearing and raising children because it may entail significant struggles and sacrifices of it’s own. So it is OK not to be happy about using NFP. It is OK to be angry or sad that it is necessary. And many of us must grow considerably before we can regret only that it is necessary to avoid pregnancy and not to hang on to feelings that if we could only legitimately use contraception life would be better. But even when we use NFP only out of obedience (even grudging obedience) God is so very generous with His grace and blessings and grow and flourish we will.
This is the first time I have ever seen it written that it is OK not to be thrilled with NFP. After 12 years, I can say it has been a blessing, but it certainly has not always been easy, and as my body moves into more changes now that I am getting older, I confess that I am just a little scared - trusting in God, but scared. As I said, it has been a blessing and I am very grateful for it. I totally agree with the last sentence that "God is so very generous with His grace and blessings," even when the obedience is not always easy.