Does using birth control hurt my chances of getting pregnant later on?

To tell you about my brief history of birth control, I've been on the pills (Ortho Tri-Cyclen) for about 1 1/2 years now. I haven't had any bad side effects, so I've been comfortable taking them. I am 17 and been with my boyfriend for 2 years. We've been talking about having kids someday if we ever got married, and that got me worried about my fertility. I've heard that if you take birth control at a young age continuously up until your 30s, for example, it'll be harder to get pregnant. Is that true? If so, I'm willing to stop taking them for awhile.