From my point of view, it just seems that contraception is absolutely indicative of sex for pleasure. In this manner it makes sense that the church would be against it, since fornication is a sin.
I think I know now, based on a crazy mad fanatical dumb teacher I had: sex is supposed to be for two reasons: procreation (God's in between two, cause he infuses the soul into the zygote) and uniting the husbands. Then no one can have sex without being married AND wanting to have kids, unless there's a real good, prudent reason for not having kids, or stop having them (like having 12 kids and no money for more). But, if there's a good reason, then the only way you can have sex is: 1.still not separating those two things (procreation and unity) and 2.using the Billing's method, because when you do have sex on the days the woman is not fertile, is not unnatural, but using a contraceptive makes "natural fertile days" into unfertile ones, thus making the whole thing something for the only purpose of uniting the woman and man, and not procreating, and that is.....INMORAL!