Negative opk on peak day

Ashlynn • 25 and married. Living with Endometriosis. Mom of 3 December Babes and due in April 💞💞💙
So I have used opks for the past 4 days all of them came back negative, today is aupposed to be my peak day and this mornings was negative too. I'm having cramps that feel like ovulation cramps. So now I'm just confused. Any thoughts?