I need to use birth control for medical reasons and I cannot help but feel guilty and fearful for the future. ... I find it hard to trust NFP because many women don't have regular cycles (myself included) so there could be a huge chance for error thereWe are lucky to live in an age when natural methods of postponing pregnancy are no longer purely the "rhythm method," which requires regular cycles to work effectively. On the contrary, NFP science has advanced to the point where it can be used very effectively even in the post-partum period, when it's not clear for months when a woman's cycle will return. There are plenty of NFP instruction programs available for when you're ready to learn more about it.
On the other hand, charting your cycle can be extremely useful in helping determine the cause of the cycle issues. Such knowledge is not common among medical professionals, but a small minority of physicians have been trained in NaProTechnology, which aims to address these kinds of problems without resorting to oral contraceptives. I know countless women whose cycle and fertility issues have been resolved by addressing the underlying causes.
A commenter, Deltaflute, writes,
To me to NFP for birth control, it's like using a barrier method or pull out method.This is a legitimate concern, to be sure. Why is NFP be acceptable to postpone a pregnancy whereas artificial birth control isn't? The end is the same, right? Yes, the end is the same. However, we are called to love each other in imitation of God's love for us. What is God's love like? Completely self-giving. Christ gave Himself for us to the point of torture and death, and continues to give Himself to us completely in Body, Blood, Soul and Divinity every time He enters our bodies in Holy Communion. In like manner, the spouses are to give themselves to each other completely, without holding anything back--not even their fertility. With NFP, each and every marriage act allows for the full self-giving of the spouses; their fertility is not wilfully hindered as it is with contraception. If the spouses have discerned a serious reason to postpone a pregnancy, rather than have contracepted sex they abstain during the fertile time altogether, so that they don't frustrate the marriage act by intentionally separating its unitive and procreative purposes.
Some time ago, I was on a medication that could cause even lethal birth defects in a fetus, and unfortunately it takes 6 weeks to get it out of your system, so even stopping the minute you find out you're pregnant would not really help. Thankfully, I was and still am unmarried and celibate, so I didn't have to worry, but I admit I did wonder what I would do if I were married. I think it would be unconscionable not to use contraceptives in such a situation.The Church proclaims the marital act as a sacred act with two purposes, unitive and procreative, which are not to be separated by our own will. This is an absolute truth which the Church has taught infallibly throughout the centuries. This means that contraception is not acceptable even when you have serious reasons to avoid pregnancy, such as a medical condition that would make pregnancy dangerous or a medication that would pose a risk to newly conceived life. The willful separation of the unitive and procreative purposes of the marital act is intrinsically evil. Periodic abstinence, on the other hand, leaves the marital act intact and may be used when a couple has serious reasons to postpone pregnancy, even indefinitely.
I do recommend reading Pope Paul VI's encyclical Humanae Vitae for deeper insight into the why's of the Church's teaching on contraception. You will find the full text of the encyclical here.
Finally, on abortion, RA writes,
I still don't know where I stand when it comes to rape and incest...the trauma involved is so intense, I'm sure anyone would consider abortingRA: like your first commenter, I also know someone who was conceived from a rape. Her mother rejected abortion and opted for adoption instead. This woman has done so much good for so many people that, after struggling with the reality of her conception, she has realized that God has the ability to turn something as evil as rape into something as sacred as a human life. She is eternally grateful for her life, which is a testament to God's ability to turn even the worst suffering into goodness.
Longing for God,
The Catholic Wife