By Lauren Mann of the National Campaign to Prevent Teen and Unplanned Pregnancy

Today is the National Day to Prevent Teen Pregnancy -- May is Teen Pregnancy Prevention Month -- and the annual event gives us an excellent reason to look at all the progress being made in reducing teen pregnancy. The teen pregnancy rate has declined by more than 50% in the past two decades, and while that's impressive, we still have a lot of work to do.

Four in 10 teens say they've never thought about what their life would be like if they were to get pregnant or cause a pregnancy. But thinking about the risks and consequences of their actions is the first step in making smart choices. Thanks to shows like "Teen Mom" and "Teen Mom 2," we've gotten a glimpse into the lives of real teen parents -- their struggles and their triumphs -- and we've seen firsthand why it's so important to continue to work on preventing teen pregnancy.

We thank the "TM" girls for sharing their stories; in turn, they helped viewers think about risks and spark conversations about prevention and birth control. Continue the discussion with your friends and family, and put your safe-sex smarts to the test by taking this quiz. And definitely don't forget to catch "Teen Mom" Monday nights at 10/9c!