MISSED PERIOD

So my period isn't perfect but I usually run on a 34-36 day cycle & Iv been getting positive opks usually about cd18. Iv been ttc for 7/8 months now and this month I didn't get a pos opk but I missed a few possible days that I could have ovulated on and just missed doing the test that day, so I thought I'd give my period a few extra days when it came late because I figured I'd ovulated a day or two late. Well I'm not on cycle day 44 & no sign of nothing & negative test after test. Has anyone had anything like this, like is there a reason it's done this? I'm so annoyed because I thought I'd get a pos test for sure sticking it out a few days past missed period.