What Do You Do When Your Teenager is Having Sex?

Teenagers are not emotionally nor financially ready for parenthood, yet the media  keeps them in a state of sexual arousal and the result is that more teenagers are becoming sexual active. How do you handle it when you discover that  YOUR teenager is having sex - and you can't make them stop? How do you teach them about the importance of waiting until after marriage when sex is appropriate -- or do you just throw birth control pills and condoms at them and hope for the best? How should a responsible parent teach their children about sex? How can you recognize the signs that your teenager has become sexually active?