Took apart a digital

I've never taken digitals before. After 2 FR tests with what looked like evap line i tried the CB digital. Said not pregnant. That was on Monday.  This morning I tried another CB digital and got another not pregnant. It seemed to take a while to get the results this time. So curious I took it apart. There were two lines. Did some research on line because as I said I had never taken a digital before. Every article says there are always 2 blue lines no matter what. Again, curious I took apart the one I tested on Monday. Only one line! Top test in the picture is today bottom is Monday. I hate the hurry up and wait game 🙏🌈 Will obviously test again in a few days but this has me a bit puzzled.