Confuesd

Am suppose to have my period on 9th October but it came two days early that's 7th October and it started brown but heavy and on the 8th too was same and on the 9th my flow was medium and brown. And today 10th October, Nothing!. I did a pregnancy test on 6th October but was negative and did it again on 9th October and was negative too. please what might be the problem is it normal?