WHATS GOING ON!? OPK!

Candice • Trucks & Cows ❤️
This month is my first time ever using OPK. So, my period started on 6/19/14 and lasted 5 days. I took an ovulation test on CD8.. And it was negative but the line was visible. It's CD 10 and I took a test and it came out negative also but it was much lighter? What's going on? Glow said my ovulation started the 26th but it's now the 28th. :/ what's going on? Should i stop worrying?
​The top picture is CD 8 
 
​the bottom pic is CD 10