I remember I had a terrible headache, cramps,
and nausea
and vomiting. I also began my period a few days after I took
Plan B, and it was much, much heavier than my normal cycles. Trust me, birth control works much better, is less stressful, and is less painful if you are indeed trying to prevent pregnancy. Also, I believe I read on the package when I took it that if you have already conceived, it won't terminate the pregnancy.