Plan B pill got me or what

Lavinia

I had my period a week ago, and 5 days ago I took a plan B pill. 2 days ago i had a killer headache, and nausea (baby barfed twice). Yesterday had spotting (dark old blood). This morning woke up with cramps and nausea. And with my period. Again. Wtf. Is this the plan B pill? Cus Ive taken a plan B pill before and it never happened. (Last time was like maybe 7 months ago?)