Ovulation Test

Hi there, 

I have been using Clear Blue Ovulation Test (predicting 4 or more fertile days) and I didn't realise you're not able to switch between holders within a cycle as I had three unopened in a bag so they got mixed up but prior to this I had only been using one consistently. 

Yesterday, two of the new tests came up with a blank circle and one with flashing smiley. I then tested again today all three to see how they'd pick up reading, two had flashing smiley yet one had blank circle? Can it take more than one reading to establish a baseline? 

Also, a few months I had used ovulation tests with the original holder as mentioned. The first time ever I had used it, I got a static smiley and then didn't continue during cycle as I was not trying. Again the next month, I tested again and got a static smiley no flashing but again was not trying. 

This is the first month when I've tried using the tests earlier in my circle. I understand you said a blank circle sets a baseline but would this happen two days in a row and also it never appeared during my first ever time using them? Please can you provide some insight.