Has anyone experienced this yet? please help

Erin
In October I started taking prenatal meds. DS24 and folic acid. Last month a week before my period I started feeling very light headed and extremely nauseous. Took a test and then AF came. Only lasted three out of my usual 5 day cycle. I am three dpo and I am starting to feel the same. Very nauseous and lightheaded. Anyone experience this before?