Why would my line be lighter today than yesterday

Question

Top test is from 4weeks 1 day second test in the picture is from 4 weeks 2 days. Why would my test be lighter? I tested at the same time of the day (morning) with the same brand.

Answer

If you look at the bottom test - all of it is lighter than the top test..not just the positive line, but the control line too. Looks like there was possibly less dye in the test

Answer

Id just stop testing love