OPK help

so I think i might've started opk testing too late this cycle (this is my first cycle with OPKs in years). I'm pretty irregular but I know my period comes CD 29-36, putting my ovulation usually CD15-22. I started opk testing CD 17 because I only bought a 10 pack and every test has been Low fertility.

The lines on the test have gone from close to positive to gradually lighter. Is it possible I missed it completely this cycle? I thought maybe it would still give me the flashing smiley if I had missed?? Any help is appreciated!