Use of contraception in cases of rape is indirect, and moral. Sexual acts naturally proceed toward conception, so the prevention of conception is morally an interruption of the rape (direct) and the lack of procreation is in the consequences (indirect).
But the use of abortifacient contraception is not indirect, since killing an innocent prenatal does not interrupt or stop a rape. So the morality of the act does not depend only on the consequences.
At the time (in the 1960’s), theologians and people in general did not realize that oral contraceptives are abortifacients. That is why some theologians approved of their use in cases of rape. But given what we now know, their use is NOT moral in cases of rape – unless it can be determined that, in a particular instance, the pill will only act as a contraceptive, not an abortifacient.