When I was 17, I wanted a tattoo. I really, really wanted one.
Howver, I didn't have one, because I was sensible and decided I'd rather not brand myself with something I'll live to regret. However some of my younger friends weren't so wise and ended up having tattoos they now hate.
I seriously recommend taking a step back from this and really having a good think about whether you are comfortable knowing that this tattoo will stay with you for the rest of your life. You'll see it the minute you wake up in the morning, and you'll see it the second you go to sleep, every day, every night for the rest of your life.
Now, you're 17 and as you fully well know, the age of consent for tattooing is 18. I firmly suggest you hold off your desire, for one year. If by then, you still are 100% comfortable with the idea of being permanently inked, then by all means, go ahead with it. But, I can honestly tell you, that you will not be the same person you are now, in one year's time. A year isn't a long time, compared to the next 60 years of your life that you will be permanently tattooed and possibly living in regret.
I may sound completely melodramatic, but I'm speaking from the head, not the heart. A tattoo today, sounds fab, but in reality a tattoo in 50 years time... who knows?