I have been nauseated for 4 days now? I'm not pregnant?

Hi. Since Friday I have been nauseated to my stomach. It continues throughout the day and is very uncomfortable. I don't have any other gastrointestinal symptoms and I'm not pregnant. What could it be? I've tried eating different foods, I've tried drinking Ginger ale, even throwing up and nothing makes the nausea go away. I really want to call in sick to work, I have to be on my feet a lot at work bending over changing poopy diapers. I have noticed since being nauseated I am way more upset by smells, they seem to be magnified. I call in sick to work a lot, I al always getting sick, but I still want to call in. Frankly if I lost my job I wouldn't be too upset, I'm ready to find a new one. Should I call in? Why am I so nauseated?