Are spouts of dizziness leading to nausea a symptom of pregnancy?

The dizziness is exactly what happened to me. I have been singing for years and know that it wasn't the breathing that got to me when I was in a lesson one Friday. All of the sudden, I felt lightheaded and if my voice coach hadn't gotten me a chair, I would've been on the floor. At that time, I did feel slightly feverish and the heat gave way to nausea and dry heaving.