Evap lines are something to watch out for, but I would be waiting another couple of days & testing again with FMU just in case. I haven't heard of too many getting BFP's with midday urine at 10DPO, but that doesn't mean it can't happen I guess.

Fingers crossed that if you test again (even tomorrow morning with FMU) that you see a BFP staring right back at you.