How to stop depo shot spotting?

I got the depo-vera shot 8/7/18 and on 8/22/18 i started spotting, not heavy at all just enough that a pantyliner took care of it...well here it is 9/8/18 (18 days) and im still spotting. I heard that if you take bc pills for a few days the spotting/bleeding will stop. I still have my old bc pills from 2 months ago before i switched to the shot, my question has anyone else tried this? I would love for the spotting to stop! Is it okay to double up on bc's like that?