How do you get phlegm out from your throat?

I had a cold about a week ago (but I recovered), but since then, my throat has been clogged, and sometimes, it gets so clogged, I can't even breathe through my mouth. I'm in school practically 24/7, and I cant go to the bathroom to spit it out. (DAMN, I sound so disgusting) Does anyone know of any cures I can use to clear up my throat and get all of that phlegm out of it?