Ovulation Question!

Hi,
I have a picture of 2 ovulation sticks taken approx 6-8 hours apart.
As you can see neither are positive but one is darker than the ther..
Top ovulation taken early afternoon - darker but not as dark as test line
Bottom ovulation - barely visible line.
Does this mean I either ovulation in between these times or i possibly didn't ovulate this month? 
Thanks