Birth control and nausea

I just started taking birth control about a week ago, and I've been extremely nauseous since then. I know an upset stomach and nausea are common side effects, but it's gotten to the point where I can't eat much or move around too much or I'll vomit. I was wondering if anyone else has had this level of discomfort, and when it went away for them. I take tri-sprintec, if that makes a difference.