And that's just it Care, YOU have the right to use or promote BC all you like and still call yourself Catholic. Now the Church says if you are doing so, you have sinned, but a 'venial sin.'
CATHOLIC ENCYCLOPEDIA: Sin
For those non-conversant with Catholic Doctrine, trust me, it's worse than the Senate.
Nevertheless, the Church just hopes one day you'll see the light. In the meantime, don't get in vitro or slice the tubes. Well ok, the later is there with the pills, those other? Nope, mortal sin. Right there with abortion.
With all of that said, it still hasn't anything to do with the first amendment and religion.
This post probably has wrecked the chances for all the atheists to come knocking on the Church font. Oh well.