November 30th 2016 I Had My Period And It Lasted

November 30th 2016 I had my period and it lasted 4 days as usual. And I had sex the 3rd the day my period ended and I had sex the next day on the 4th without pulling out. Then again the next weekend and lastly on the 18th but on the 18th I had drips of blood during sex. Then the 21st I started my period and it was 1 week early and now I'm on day 6 and I have Brown discharge with a light smell with light cramps and back pains can someone tell me if I had my period and I'm pregnant or is this something else? HELP