nees help understanding my chart

hi! i need help understanding my chart please? i cant tell when i might have ovulated. i was using the clearblue advanced ovulation test kit but it kept giving me the flashing smiley face (high) for 7 days and then i ran out of strips, so i wasn't able to finish testing. Now my period is 12 days late and ive taken 4 pg test and they read negative. I've used 3 dollar tree brands and 1 of Walmart's .88 cent test. I thought about trying a different brand i have tempts that are in the 98's and they fall down into the 97's. I dont know what to think. Tia!