Had sex. Why did I spot in brown? Possibility that I'm pregnant?

Ok my period wasn t due until the 16 it came on the 12 stayed for 3 days then went on so I had intercourse on the 15 spotted on the 16 had intercourse that night and spotted the next day I stopped bleeding altogether on the 17 that was on a Monday that Friday I had two spots of brownish spotting it looked like dry blood the next day I had excessive white milky thick discharge with 2 tiny brown speaks of discharge I ve been feelin nauseous and fatigue slight cramping the 1st time my bf ejaculated in me was on the 8 then the 11 my menstrual started on the 12 today I vomitted an took a home pregnancy test and it was negative so is there a possibility that I m pregnant and took the test too early