sick while working

I am about 6 weeks pregnant, and I have a full-time job teaching. It's tough, because when I don't feel good, I mean. My sickness doesn't happen at the same time everyday, and the same things don't trigger it. I am constantly sniffing peppermint oil, and that puts it off long enough for me to make it to the bell and then puke in the bathroom. Who else is doing this? Any advice?