Am I pansexual?
No. The subtext that's coming through what you said is that you like boys, if you like boys and not girls that way you are heterosexual and not any kind of bisexual.
Forget all the fancy labels. You are 13 and have not grown your "big girl wings" yet- meaning you haven't figured out all your feelings. Heck, I didn't figure out that I was a lesbian until I was 25 and married. (aaaaaaarrrrgggghhhh) Couldn't figure out why my marriage was so lame. I didn't know any better back then. Long time ago and no info available. Give yourself a little more time. Call the gay center and talk to the counselor and other girls your age. Relax. Enjoy your life. Don't make it any more complicated than it is.
heart o' gold
You are probably too young to know for sure which way you swing. I suggest not worrying about labels and focus on school.