What you called " having sex " out of marriage is called fornication and adultery in the Scriptures. Since fornication and adultery always happen in the worldly realm of " dating ", then yes you get unwanted pregnancies/STDs from " dating " !
" I've never read about courting, purity rings, Christian t-shirts, the Internet, surfboards, rollerskates, computers, iPhones or television in the Word either. Doesn't make them evil. "
Logical fallacy.
Since the Lord created the man in His image, the man has a natural wisdom to create all kinds of useful things.
But we live in a fallen world, and " dating " doesn't come from natural wisdom, but from the world's fleshly spirit :
It's written : " For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world. " 1 John 2:16