First response ovulation test vs clear blue digital ovulation test

So I took the first response ovulation test first thing in the morning and the line was about 75% as dark as the control line, so not quite there. Then, around 3pm after holding my bladder all day I took the clear blue digital ovulation test with the smiley faces and got a blank, not fertile result. According to glow I have a 15% chance of being pregnant and I'm on day 14 of a 31 day cycle. Has anyone else had this issue with their ovulation test and what does it mean? This is our first month at trying for baby number 2.