Thought I ought to introduce myself to the general masses, so here it goes

(I'll try not to make it too lengthy, ha)
I'm exploring my gender identity, and feel rather strongly that I might be FTM transsexual. But I feel self-conscious saying it, because I feel like if this was really the case, I should have known from a younger age. I feel like I should have been more... defiant of being considered a girl, all this time.
The earliest memory I have regarding my gender identity is... early. And reoccurring. I remember when I was very little (kindergarten age, probably,) I would often just stare at myself in the bathroom mirror, usually from the nose up, for a very, very long time, until I slowly became certain that the reflection looking back at me was undeniably male. Not because I wanted it to be; it just was. And every single time I did it, I scared myself near to death, because I was born a girl; obviously, I was a girl, right? Those moments staring in the mirror challenged what I thought should have been a simple fact.
I've never been exceptionally discontent with being considered a girl. I mean, I've always just expected it. But being mistaken for a boy, or being affectionately dubbed a gentleman by my friends, or being called to help my dad in the garage because he knows I'm the toughest kid in the family... those moments have been the proudest of my short life.
I played the boy characters in every imagination game my sisters and I played, growing up. And it's always made me sick that I can't audition for school plays with realistic hopes of getting the male lead. Little things like that, where looking back, I realize just how much I've been quietly pining. And I have to believe that I've always been quietly pining over this hidden wish to be male.
So. That's about the gist of it. I can't deny that I'm very self-conscious about all of this, because (while I was always raised to be accepting of everyone,) it was sort of instilled upon me at a young age that no one had any reason to be unhappy in the body/gender they were born with. I really think that shuttered viewpoint is what's kept me from exploring this until recently. But you have to face this stuff eventually, right?
But enough of that. It's very nice to meet you all.

I'm hoping this site will help me convince myself that it's okay if I'm transsexual.
You can call me Nic.