I didn't get a tatoo until I was 18 because my parents wouldn't allow it before I was legally allowed. If you wait a few years, they'll still be tatooing. I think its great that you're not just jumping to get one right away, that you're thinking about it. Sounds like you've got a good head on your shoulders. If you wait, you'll know for sure that you want the design you've picked. Trust your gut on this one. If you have doubts, why not wait a bit?

Apprehension is usually a little warning from our intuition saying uh yeah.....maybe not right now....trust that intuition.