We can all agree that nobody has a right to that which is impossible. Since no contraceptive method is 100% effective, we can take this principle and say that fertile couples do not have a right to pregnancy-free coitus.
Not many people outside of Catholic pro-life circles know that SCOTUS agrees with the Catholic Church regarding the link between contraception and abortion. The difference between them is that SCOTUS uses the link to uphold abortion, whereas the Catholic Church uses the link to condemn both contraception and abortion. Here is SCOTUS in its 1992 decision known as Planned Parenthood v. Casey:
“…in some critical respects abortion is of the same character as the decision to use contraception . . . . for two decades of economic and social developments, people have organized intimate relationships and made choices that define their views of themselves and their places in society, in reliance on the availability of abortion in the event that contraception should fail.”
Catholics talk about “the contraceptive mentality,” and this is what they mean. The contraceptive mentality is when people believe fertile couples have a right to pregnancy-free coitus. If we accept this idea, abortion makes sense. This is precisely what SCOTUS did. It accepted the contraceptive mentality, and upheld the “right” to abortion as a result.