what does it means when you cramp like a whole week after your period?

This doesn't usually happen to me. I mean I've always cramp like the First 3-4 days of my period then it stops...(without medicine)then the cramps will automatically go away after that process.But I won't cramp at all if I take Pamprin MAX. Strangely my last 2 recent periods I've began to cramp like two days after so I want to know what these signs can possibly indicate. (this have never happened before).! These particular cramps feel as though im on my menstral.....except like a lil more severe.