Stomach ache, virus, birth control, food poisoning?

Yesterday afternoon I started feeling really nauseas, and ended up throwing up twice at work. At that time my stomach didn't hurt, but I was very nauseated. I came home and started throwing up more with bad stomach pains. I started taking Yaz last week but it didn't make me sick. But I also ate some chocolates at work that I later found that mice had gotten into (they were wrapped Hershey's kisses). I was up all night last night throwing up, I can't even keep toast down. I have a low grade fever with chills. And am very achey.