Birth control is not the wilful destruction of human life, so it is not murder.
It is, however, the refusal to consent to God's will. God desires that marriage leads to sex and sex leads to children.
Incidentally, the command to procreate is the first one given to Mankind after the fall of Adam, "Be fruitful and multiply."
And then children leads to no sex, bills out the ass and a lot of headache from worrying about them all the time.
It might be if it is an abort-efficient as many pills now are.