Is this a sign of early miscarriage?

I’ve taken 3 tests. Two were with FRER and were kinda faint but clearly positive (12 DPO and 14 DPO). Both were with FMU, but there was not a clear progression. Today I am 15 DPO and decided to take a cheap Dollarama test just to confirm. This one looks pretty negative to me. I took it in the middle of the day, maybe a 2-hour hold, so maybe it’s not that reliable, but I thought I’d see at least something. (There is a little blip on the dollarama test—not sure what it is, but it’s on the inside of the screen, not outside. I didn’t notice it until after I tested.)

Just wondering—could this be a sign of an early impending miscarriage? Either way, how long after a newly negative test does a miscarriage typically start? I am emotionally neutral about this since it’s so early, so blunt honesty is appreciated. Thanks!