Then there's the case of Adam and Eve ~ now how'd that happen eh?!
In this brutal age of rough people let us celebrate the arrival of another new life. The rest of it is just ceremony.
Divorce was permitted in the Old Testament, but it was not approved by God.
Some of the patriarchs practiced polygamy in the Old Testament, but the practice died out while monogamy remained.
As for Adam and Eve, the first man and woman were declared to be husband and wife by God.
You have not named a single culture that practiced this “fertility testing” before their community considered them to be married.