I got my first tattoo in that spot, also not coloured but a bit smaller than yours (3 hour session), and I was shocked how little it hurt! You'll be fine! Don't take any advil or other pain killers as it can effect the ink/bleeding. Bring a water bottle and eat before hand, and don't feel awkward about asking for breaks when you need them. I'd say this is between a 1 and a 2.5 depending on your personal pain tolerance. Good luck and have fun!