No positive opk?

Ashley
Aunt flow is fairly regular and this is the first month that I've been taking ovulation tests. I've take 9 and gotten nothing. So it's pushing aunt flow super later, which doesn't make sense. 
I take them in the morning. Is it possible that I'm not taking them right? Or have I just not ovulated? 
This is our 3rd month ttc. 
UPDATE: I just took one at work and got a positive OPK. I'm apparently an idiot. Haha send positive vibes and baby dust my way.