I am 14. I kissed a girl 2 months ago and my world was turned upside down. I LIKED it... a lot. Ever since then I notice myself checking out girl only. I noticed before that I checked out some other girls too. Am I lesbian? Bi? How do I know??
By relaxing, waiting and seeing what happens. There's no rush, especially when you're 14! You'll figure it out; it might even take years to find the extremes of who you're attracted to. Don't worry about it too much and good luck!
It might take time, like Connorcode said. What I like to do is to focus on what I know for sure and take it from there. You seem sure you like girls, right? Well that's good, then you've got that one in the bag. That leaves boys then. Maybe in time you'll find that you're attracted to guys; and maybe you won't. And either way, it's fine. NOw, I get it if you're looking for a label. But maybe saying something like "I like girls" or "I'm mostly interested in girls". Because that's true; and it neither includes or excludes guys, which might work for you if you aren't sure.