Based on your timing, I don't think your symptoms are pregnancy related. That's because typically, pregnancy symptoms like vomiting usually don't start until after you have implantation and implantation is most common seven to ten days after you ovulate. So even if you did conceive, it's unlikely that implantation has happened yet. The more likely cause of your symptoms is a stomach virus, since it's the season for those.
That being said, any time you have sex there's a possibility of becoming pregnant. I would hold off on taking a pregnancy test until you're about four days away from starting your period. At that point, if your symptoms are pregnancy related, then the test will probably be able to turn positive by then. If it comes back negative and your symptoms don't clear up, let your doctor know just to rule out an infection.