cramps?

So, I just ended my period about a week ago, but I have been having bad cramps like I am about to start again. I always have really bad cramps when I am on my period, and while these aren't as intense, they are definitely strong enough to notice. The cramps are not continuous, they only last for maybe 20 minutes at a time, but I've had them multiple times a day for the past 3 days. Any advice or idea why this could be happening? thanks in advance, ladies!