I tested on Friday using a promatris one step test (the nhs use these too) with fmu. A couple of seconds before the 10 mins was up I checked and there was a 2nd pink line. It was not as dark as the control line and it was thicker and blurry. I used the same tests and same lot number this morning using fmu and all were negative. Do you think fridays resuts was false or an evaporation line? or could todays all be false negatives despite using fmu again and the tests all being from the same batch?