12dpo!! BFP or evap?! Help!!

This test is 3 hours old! Which I KNOW tests should be discarded after 10 minutes, but let's face it we've all looked at old tests! Now, I know this could very well be an evaporation line as it is an old test, but the line has color to it! I know it's thin, but any advice would be awesome! Has this happened to anyone before and it turned out to be a BFP? I'm not getting too excited yet!