Is getting married atfer high school too young?

My boyfriend and I have been dating officially for 6 months( today is actually our anniversary). Before that we had been friends for a year. He asked me to date him once, but I turned him down. After realizing I wanted to settle down and I liked him too and he still liked me, we made ourselves an item. We've been smitten and inseparable ever since. We are in love and want to get married for sure, but just don't know when or how. We're in high school. He's a senior and I'm a junior. When I graduate, I'll be 17. My mom has already said she won't consent to me getting married right after high school. I plan to go to college and then med school then a residency. He wants to be a merchant seaman. Both of us won't be seeing much of each in those careers, so we're trying to plan around each other. We want kids, but I want to be done having them by 30(and not during med school or before marriage). Most people say it's best if you're not married in med school. What should we do?