emergency contraception
"I took Plan B One Step 7 Days ago (Sunday). I was days before ovulation and fertile at the time so I took the pill the following day (Monday).  I had no side effects. However, recently (Friday) I was extremely dizzy and had a massive headache for about 2hrs. So I ate, relaxed and laid back for a minute and it was gone. So side effects can come days later. But hopefully like mine they are short lived. I still haven't gotten my period but it isn't due for a couple weeks."