Ok, so I just tested and got a faint but there line on a Wondfo. Tested with the same urine on a FRER and got a stark white test. Tested with same urine on another Wondfo (because I'm obviously crazy) and got an even lighter positive.

What does this mean?? I thought that FRER were supposed to be the most sensitive.

I think I'm 13dpo.

Pics are of first Wondfo.