Morality, how it's defined, changes with time and place.
And in times past, birth control was in the hands of woman, who were far better versed in the use of herbals. The lack of unwed births (which I won't even argue... as shotgun weddings were prolific as were "premature" births, as compared to today...) was more due to the consumption of abortives than due to making the "hard choices".
Not to mention other options... meaning orifices, that are considered "improper" by those same moralists. And today... a teens are very willing to call themselves virgins and chaste because they don't have vaginal sex. Oral (nor anal) isn't even "sex".... they know because Bill Clinton said it wasn't.