Do u think my girlfriend is avoiding me?

well at school today, i saw her in the morning, talked bla bla bla. then at recess i didnt even see her at all, at lunch i saw her twice but when i went after her, she walked around the corner so i followed her then she was gone. then after last period, i saw her walk out the door first (we usually walk together) and as soon as i got out she was already gone. Why is she doing is? and should i call her now and ask why did she avoid me or ask her tomorow if i can?