Nausea and migraines

Patient: I have been experiencing migraines with nausea for about5 months now and my nurse practitioner is having no luck relieving me of these. I have been switched from two medications, celexa and Wellbutrin, to just Prozac as that was thought to be the cause but I haven’t had any relief after three weeks of being on the new medication. Do you know what this could be?

Doctor: