Blue Dye False positive?

I used an Acme store brand test and I thought I had a negative but I looked again 30 minutes later under the light this time and it appears there’s a line. I don’t think it’s an evap line because I see the actual color blue. Don’t blue dye tests have a lot of false positives? Could this be one? I don’t trust anything. I’ve had four miscarriages, the last three in a row within a 9 month stretch. I haven’t been pregnant since April. And IVF is on the calendar for January. I have one more test but I’m saving that for the morning.