Teenage pregnancy is such a problem now and I dont understand why.
One of the concerns of teenage pregnancy are the same concerns for other pregnant women but in addition to that, those under 15 are less likely to physically be able to sustain a healthy pregnancy, they may not be physically developed enough to give birth. That is definitely a problem
I have heard some school even have day cares now
Yes, roughly 80% of teenage pregnancies are unintended, part of the reason why is because some cultures limit or discourage acress to birth controll. They consider it to be morally or religiously bad. People also harass planned parenthood clinics, this leads to less acess to resources at risk pregnant teens or pregnant teens need
I think it could be the media putting out suggestive messages that is causing some of this.
Yes, some media output, some religious output, and also the lack of competent s-x education plays a part. S-x education is supposed to cover all aspects relatedto s-x but a lot just preach abstinence only instead. 
I think it rest on the parents to teach their kids about it so that they can prevent unwanted pregnancy.
Yes but some parents lack the competent s-x education options themselves. They know how to do it and what some risks involved are but not the full scale of risks or options, and parents will automatically discourage s-x behavior instead of preaching safe practices. Also sometimes the incorrect use of a contraceptive method can contribute to unwanted pregnancies, some parent teach to use a cond-m but not how to.