Only two sticks remaining...

I have two Clearblue Advanced Digital (CBAD) test sticks remaining from an old pack and I want to use them to potentially highlight a high fertile period. I want to use another test until the results are "close" to positive and then will switch to CBAD to see if my prediction of high fertility is correct and hoping to see a flashing smiley. Will this scenario work or will only two tests not be enough to identify a significant change in my hormone levels to properly identify the high fertile window? TIA