Please I need your insights.

First off I have implant on me, so period has been inconsistent. For the past week I have been having period cramps on and off with lots of discharge but no period. Now yesterday I saw a small bunch of brown discharge and then I used the cotton bud and and I got this when I wiped. After then up till this morning there wasn’t anymore. I took a pregnancy test and it came back negative. What do you think this is?