I'm almost eighteen. lol
okay, hold the forget up.
i think it's absolutely fine you're happy with your girlfriend and you're both happy and all that, that's actually good. congratulations!
but it's SERIOUSLY WAY TOO EARLY to be thinking about marriage. i don't know about you but i wouldn't even dare think about marriage until i have a stable income at least unless you want to just be mooching off of one of your parents for a long time.
please, if you care about your future, just hold off on marriage. if you want to live together fine whatever do that, but don't get married yet. it's a very big decision and if you haven't even been dating a whole year it's very careless to jump into it so quickly.