Brown discharge ??

So on January 22nd, I began taking the vaginal gel to treat BV. It was my first experience with BV as well as the gel. I finished my treatment on January 27th. Yesterday, February 4, I noticed brown discharge when wiping. I’ve never experienced brown discharge unless it was the ending stages of my period. I have been on the nexplanon implant for 2 years (last day will be December 17, 2020). I stopped having periods 4 months after insertion. I had one period last year around this time/March so I figured i’ll probably have one again this year around the same time. I’m not sure whether this is just my system cleaning itself out or not but should I be concerned? Last time I had sex was January 18th (explains the BV 🙄) and my birth control never has failed me before (🤞🏽) so I don’t think i’m pregnant lol. He did ejaculate inside of me though. I still have not seen any blood or experienced my usual pms symptoms. Today is only day 2 since i’ve seen the discharge. Should I wait it out to see if my period comes or what? Or is it a possibility that I could be pregnant? idk! I need some advice!!