Could The Bleeding Be Due To Miscarriage Or Withdrawal Symptom Of Norethisterone?

Hi I have been taking norethisterone 5mg three times a day for nine days when I thought I had become pregnant The test was positive so I stopped taking the tablets I was on a ten day course now four days later I have light bright red vaginal bleeding is this a miscarriage or breakthrough bleeding from stopping the norethisterone? Please help Im so confused???