If you check Native american You better be able to prove it with documentation. I'm 1/4 cherokee on both sides of my family but I never check Native American because I'm not documented. If you can't prove it they will probably be a little upset.I can prove it I just never took advantage of it. I have talk to my grandmother to get the nemes of my ancestors. Then I have contact the Cherokee Nation to see if thier names are on the membership rolls if so then I have to petition the Feds for Blood Documents stating that I'm Native American.You don't have to look Native American to be Native American. You just have to be honest with yourself and not be a racist prick.
I am 1/4 Muskogee Native American, and I check the box because I ALWAYS have. When I was 6 years old taking my first standardized test, when I didn't even know what AA was, I checked NA because my grandmother and father had made me proud of my culture. Its a part of who I am. It doesn't sound like this is the case with you, please don't check it.