Okay, I know this is kind of gross but...?

I have a really bad cough and have to spit out phlegm like every 2 minutes. I need to go to school tomorrow because of an important test we're having. How should I spit out phlegm at school? I don't want to keep asking to go to the bathroom, nor do I wanna get up and walk to the kleenex all the time. Anyway, everyone else only uses them to blow their nose. I've tried carrying some tissues in my pocket but that's still kind of gross, plus I don't want people to see me spit, period. Help??!