Ok just hear me out...

I know y'all are going to say this an evap. And it very well could be I won't deny that, but this is the second day in a row that this happened to me. Please remember that I have taken dozen of these tests and have never gotten an evap. The only lines I've gotten was from my chemical last month and they were true positives. My test was negative the first 10 min (or so appeared) I look back at it and see this line. Clearly colored, and obvious. I can't help but wonder if these are actually evaps or if the tests are just taking longer to show a reaction. I guess we'll find out when I use my frer tests! Any ideas?! Thinking its a possibility that the line was there to begin with but too faint to see and it darkened after time? Again, I know these really might be evaps and it could be that I just happened to get two that show evaps for the first time, but it really makes you wonder...