Teen pregnancy (or unwanted pregnancy at all) has been extremely low in several countries, and the factors are not discipline but was of access, focus on health instead of morality, and public service campaign. If it is high in an otherwise rich country, it’s likely not a lack of discipline from teenagers but a lack of free and easy access to contraception and abortive means, social pressure and morality campaigns, lack of sex education (often by design sometimes by negligence after some period of activity)