[causi]

People around the world routinely engage in frequent sexual intercourse without becoming pregnant

Yes, and people routinely take methamphetamine without having a heart attack and shoot themselves without dying. That doesn't obviate the fact that pregnancy is the direct result of coitus. Claiming you did not consent to the function for which a body part evolved when you used that body part is like saying you didn't consent to sweating when you went for a summer jog. Sure, you may certainly take measures to prevent an undesired outcome but the physical results of your choices can only be tragedy, not injustice.