Is FMU really unreliable?

Falen

I know I wasn’t supposed to take this with FMU but I just couldn’t wait since (sorry TMI) but I woke up with a lot of EWCM. So I peed in a cup and got this guy! Premom registered it as a high/my peak and glow just can’t read an OPK it seems... safe to say this is my positive?!?!