If you start down that road, it will lead to places you'll regret later on. If you're not ready to take it that far, don't experiment.
The best advice is to work on your education and career before getting involved with boys. If you end up pregnant and this guy turns out to be a jerk (trust me, they can act like the perfect guy until some responsibility comes up), you'll want to be able to support yourself and any future children you may have.
Work on your life first. Don't worry about that stuff (it's a big waste of time).