OPK help!!

Hello 😊
I usually have a 23/24 day cycle. Today is cd15 and this is my opk test?! 
AF is due in 9 days. Surely this is far too late to conceive? 
Il test again later/tomorrow to see if it's darker but all other tests I've done leading up to this have shown no line at all. 
I'm fully aware that it needs to be darker than the control line to be positive but this is defiantly more positive than any other test this cycle. 
Help and advice please!
Thank you 💜