Pelvic cramping

I always have cramps during AF and during my fertile week I always have left or right pelvic cramps but I don't have any kind of cramping any other time... I just got off my period and I'm having left and right pelvic cramps (it alternates) like I do when I'm ovulating but I shouldn't be ovulating for a couple more weeks... This is day 6 and I ovulate day 17... Have any idea why this is happening now?