Since when is using contraception a responsibility? That implies that not using contraception is irresponsible.
It's responsible to use a contraceptive when you don't want a pregnancy. It's irresponsible to not use a contraceptive when you don't want a pregnancy -- except in the case where not using a contraceptive because of religious beliefs. Then it is neither since ostensibly the couple will accept whatever befalls them. I.E it's unlikely that people not using contraceptives for religious reasons would then use abortion as a form of contraceptive.
So no, your inference is wrong because your inference is incomplete.