The R.C. church has adopted this stance on contraception by a convoluted thought process that has now entered its 'holy tradition', to which they attribute equal authority to scripture.
The Bible teaches sex within the bounds of marriage, but what was marriage originally, except a man and woman deciding to live together .... and have sex? Then, according to scripture, they became, "one flesh."
God gave us the gift of sex for, yes, procreation, but also to enable us to express our love for our husband / wife.
To put man made prohibitions on sex is not only wrong, but obviously unworkable.
The same can be said of enforced celibacy, which is also not biblical.