Ovulation

Hello,

I tested on Sunday morning and it showed a flashing smiley face, then tested again with the same clearblue digital kit in the evening and it was still a flashing smiley face. And as I am trying to conceive I tested again on Monday morning with the same kit and it was again a flashing smiley face. After that as I run out of tests I bought another pack and test in the afternoon with a new clearblue digital kit which came back as an empty circle. Can someone explain this please?? I am really worried and wanted to understand what’s wrong. All other cycles in the last came as static smiley face. Please help!! Thank you!!!