Can a trigger shot false positive reappear? 12 DP trigger & 11 DPO

Hi everyone! I am posting this with a more specific question:

I tested my trigger shot at 9 DPO with a FRER and got a faint line , but undoubtedly a false positive. I tested again later that afternoon on a FRER and got a stark white negative. I tested on FRER again this AM (11 DPO) with FMU and got a vvfl. Could this still be trigger even though I tested negative in the afternoon on Friday?