Do you believe you can find your "true love" at the age of 18?

My boyfriend and I have been together for 3 years. He is my first boyfriend and I am his first girlfriend. I really believe are relationship is different then all those couples that “recycle” each other in high school. I am 18 now and we always talk about marriage and our veiws on family are the same. Are we to young to think this way? Should we date other people since this is both are first relationship? Or is the relationship we have meant to be?