Negative hpt but period is over 2 weeks late,

My period is late for over 2wks, I'm always on time, but I did 2 hpt both says negative, but in the mornings I'm vomiting a yellow substance, I have nausea, headache and dizziness it seems I have all the early symptoms, but I don't know what to do, I have a doctors apt next Friday , until than can anyone relate. Thank u