Contraceptives

I still can’t quite wrap my head around the Catholic stance on contraceptives… It feels (to me) a little invasive and quite frankly like a logical error.

For reference, I’m (hopefully) about to get married to my beautiful girlfriend, and will be going into the US army soon after. While i want to serve my country, I also feel that it is kind of irresponsible and bad of me to have children while i’m actively beginning my service. I don’t want to risk having children for at least the first few years of my marriage. This is a personal decision of her and I so we are able to appropriately plan for the future (and i really don’t want to miss one of my kid’s birthdays). I want my kids to grow up knowing about my military service, but not actively affected by it.

This being said we both know about Natural Family Planning and all that, but I am not confident it is an effective method. (Her sister in law had two children on accident basically) I don’t understand why we aren’t allowed to take extra precautions with intimacy to delay children until we decide we are fully confident and ready. It feels exactly the same- just one is more risky.

I hear the argument of “oh well we shouldn’t disrupt God’s plan” but that feels kind of goofy considering that people get medical treatment in hospitals all the time- which leads to a whole other set of questions.

Also, I hear there are medical complications that can arise if you DONT use it- for instance if a couple engages in intimacy during pregnancy, it can cause complications for the baby if the man continuously deposits semen into the vagina. (the way the catholic church expects y’all know the drill). Also, if the couple engages in intimacy after birth and immediately gets pregnant again, I’ve heard the woman sometimes has trouble breastfeeding (which is what’s happening to my sister in law).

Ive been thinking about this constantly and the best logical argument i can think of is “If the goal is avoiding pregnancy either way, what is the moral difference?”. With that most people would say “because you’re altering a natural process in a way God didn’t intend.” And my response would be, “we alter natural processes for our benefit all the time- what’s the difference here?” We have no problems morally as Catholics to essentially bring people back to life with medicine, why are we so against using contraceptives if fundamentally they are so similar?

Would my wife and i be in “mortal sin” if we disagree together and decide to use contraceptives anyway? Are we allowed to disagree, or do I just have to accept it?