The irony is this is an allegory for two cities who "committed adultery" against the covenant relationship with God by becoming bedfellows with pagan authorities in a "lust" for power. This isn't actually about sex just very strong poetic allegory to raise awareness.

The act of abortion has existed since 1000 BCE with the earliest being 1550 BCE. Around the estimated time of the mythical Moses. Obviously not as effective, but the practice existed. Not to mention sex isn't one specific act. There are many ways to have sex, even by biblical standards, that do not involve the possibility of getting pregnant.

> If you get pregnant and are unmarried, your life might as well get over.

Not really. And biblical times does not mean people's lives were run according to commandments in the Jewish bible (neither in ancient Judea nor elsewhere).