Do I love my best friend?

[geleo]

I feel jealous, weird and basically speechless. Really, I have no clue at all.
For about a year ago, a little less I met this girl at school, and after that we have been hitting it off pretty good. She understands everything and so on, basically perfect best friend. Now, the last 2 months that feeling has kinda changed, at least it feels like so.
I notice I start caring much more about what she is doing and so on, no idea why even..
Now, since school is over we haven`t seen each other at all, and that kinda irritates me sometimes. However, we are supposed to meet in a couple of days. Sent some sms with her for some hours ago, and we agreed on meeting each other and so on. Actually we planned this last week, but she was working the hole week and so on. She found out today that she isn`t working anymore of this and next week, so there was a lot of time. But suddenly, I find out about that she is with one of my best friends from that school. Now why didn`t she ask me in the first place, and why didn`t she even mention that she was visiting him. I found it out by talking to him, I find that a little bit weird actually. Since I asked what she was doing and so on, and she said she was bored and just watched television before she went to bed. But all that time, he was there. And, he lives like 1-2 hours away from her, so it don`t sound like a spontaneous thing either...Maybe I am digging way to much in to this...
Now I ask myself, this isn`t a big deal at all, I mean we are friends. Why should I care at all? This is like a normal situation, but for some reason I do care. It kinda hurts in a way, don`t know if I got the hole story presented here, but I think you get the main idea. So...do I really like her? I have no idea. Someone please light up the situation, because I am totally lost right now...