Brown discharge and lower back pain

MJ • TTC for 4 years

Hello ladies. Had my HCG shot last October 23 then on November 8, I supposed to have my period but I ended up just having a dark brown discharge starting 11-11 until now 11-14. It don’t fill up the entire pad. Took pregnancy test but they are all negative. I’ve lower back pain now too. Is the brown discharge considered as my period?