Opk frustration.

Mrs.🅱️ • Mama 👦🏼 • 👼🏼 • 👼🏼 • TTC 🌈
I'm so frustrated, and confused. I'm on cd25 (I have pcos and very irregular cycles...my last one was 41 days, before that 56) My last cycle I never detected ovulation (I wasn't very good at checking my opks to be honest). 
So, enter this cycle. I've been taking my opks since cd 10. 15 days of testing at least once a day, and nothing. And by nothing, I mean nothing! No second line visible AT ALL until a few days ago when the line was so very very faint. Now, I'm back to this; 
Have any of you experienced this and gone on to ovulate that cycle? Should I keep testing? Should I give up this cycle?