My best friend didn't say happy birthday?

Okay, so my fourteenth birthday was today. it sucked. i went to see a movie with my best friend in the whole wide world (or so i thought) and she ended up bringing her school friend (we go to different schools) and her friend pretty much hates me. Then, she didn't even say happy birthday to me, infact she barely even said hi. no texts, calls, ims, facebook, nothing. I ended up going home from the movie early because my stomach felt sick. when i got home, i even sent her a text, and still no happy birthday from her. This made me pretty hurt, i guess. so anyways, should i like confront her? or get mad at her? or just forget it, maybe she was having a hectic day?? ugh. is this what best friends are SUPPOSED to act like?!?!? :(