If your period isn't due for a couple more weeks, then it's unlikely you're experiencing pregnancy symptoms already. However, if you're not charting your ovulation then it's possible you've ovulated earlier than you expected and that your symptoms are indicative of pregnancy. That's the frustration with hormones - whether they're from ovulation, PMS or pregnancy, they all kind of feel the same at first.
Since I don't know when you ovulated (or when you will) the best thing for you to do right now is hold tight and wait to take a pregnancy test until four days before your expected period (and make sure it's an early result test that checks for the lowest level of pregnancy hormone).
Until then, if the throwing up and diarrhea (which in itself is not a typical pregnancy symptom) continues then you should call your doctor. You might have a virus or infection causing you gastrointestinal distress.