No positive opk yet- still a chance?

Be
So I usually ovulate around cd17, which is today as I'm not even close yet according to my opks. I'm trying to not stress, telling myself maybe I missed my surge (I only test once a day) or that I'm ovulating late. But I can't help but worry just a little since this has never happened before. Is it still possible to ovulate having not gotten a positive opk