Fertile wk, but no +opk?!

According to both pink pad and glow this was/ is my fertile week. I started taking opks Monday, and not one of them has shown any sign of being positive!! I am using the First Response ovulation (line, not digital) and I haven't even gotten a close to pink line. Has anyone else not had success with these? :( I'm starting to think I missed my most fertile day! CD11, and decreasing bbt? :( -sigh-