SPOTTING !! HELP!

My period was over a week late and after constant doubt I finally decided to take a pregnancy test, which came out negative, but now I'm not even sure if there was a faint line or if I'm just trying to convince myself that there was. Anyway a few days later I got my period, and bled for about 5 days. It's now a week after my period and I've suddenly been spotting a brownish/pink. What does this mean!!