Am I bisexual or a lesbian???

Hi! I'm a teenage girl and I'm questioning my sexuality. I used to think I was I was straight and when I was younger I only got crushes on guys.  I didn't get any crushes at all for about two years. A few months ago I got this crush on my best friend (who is a girl). I got over that, but since I've only gotten crushes on girls. I've always felt somewhat attracted to girls, but I shrugged it off until recently. I thought I was bi, but now I don't really think of guys in a romantic/physical sense that much, mainly just girls. If it matters, my attraction to girls has been mainly emotional, but a bit sexual. I'm confused, and I don't really know what I am. Do you think I'm bisexual or a lesbian (or another orientation)? Thanks!