The best birth control in the world is having a teen take care of infants/toddlers for an extended period of time. I was lucky that one of my cousins had her first child when my daughter turned 12 and her second child right after my daughter turned 14. She had 4 summers from 12-16 of looking after one or two kids under two years old. She swears she’s not having kids ‘til she’s 30.
Apologies for the double post!!!
You’re right, the reason most teenages have sex is to have kids! Once they know how much responsibility it requires, they won’t even think about sex!