What could it be?

I started feeling crappy Saturday afternoon. Developed some stomach issues; nausea, diarrhea, loss or appetite. I also keep getting really hot and light headed. I've only thrown up a couple times on Sunday. I haven't been eating but I've been trying to get as much fluid in my system as possible. Today makes 5 days of feeling like this. I've considered pregnancy but I just had my period March 17. Is this just some sort of weird virus (no one else at home or work has had this) or could it be something else? If I go to the doctor I have to take time off work and I'm trying to avoid that. Obviously I'm not expecting a diagnosis just some thoughts. It doesn't seem to be too serious but it's getting pretty annoying. Thanks ladies.