Teachers?

Any teachers out there who have tips on how to deal with dizziness/nausea and still teach a class? I'm only 6w3d, but my dizziness and nausea is so bad this morning that I can't drive a car, let alone engage freshmen all day. I'm going to call my doctor for coping tips, but would love to hear from you. Do I just have to suck it up? Were your principals understanding if you had to leave the class unattended?