Believe me, I'm an open minded person. But these other genders are just constructs of people who don't feel like they fit in so they can feel better about themselves. They're nothing more than an attempt to appease the ego. I truly don't believe there are more genders. If you, or other people do, that's your prerogative. I'm not going to judge you, but I'm entitled to my point of view.
Gender isn't what's Important, what's Important is authentic self. Its my belief that authentic self has nothing to do with gender. Even if you lean more towards masculine or femine. Its just part of who you are, doesn't mean you need a label for it.
That being said, if you feel better calling yourself a certain gender, you can. But don't expect everyone to tip toe around you.