I’m confused?!

I got what I assume was my period on Saturday 1/12 it only stayed on for 2 days, it wasn’t a super heavy flow but it was more than spotting, by yesterday(Monday) it was completely gone, so today I woke up and had brown spotting, something kept urging me to take a pregnancy test which I thought was completely crazy because I was JUST bleeding this weekend. Well I got a very faint line which showed up within 3 minutes, took a digital and it clearly says not pregnant, could this be a false positive?