My birth control method is to not have any sim in the Scientist Career, since I do not want undisguised aliens or abductions in my game. Only applies to those who have not yet started the career of course.
Since the game feature implicitly is about non consensual sex, you should look at your adult mods for possible interference, as well as the tips in the previous post.
This is an american 'teen-rated' forum, which means that adult mods is not to be mentioned; so perhaps also edit your post before a Community Manager does so.