Suggest Treatment For Vaginal Bleeding Even After Taking 'utovlan'

hi there, im 23 years old, about 5"3.
ive always had irregular/light periods ever since i can remember, and have been on microgynon for about 5yrs now.
about a month ago now i had a period and it caused me alot of pain, so i went to my GP and he perscribed me antibiotics for a suspected bladder infection, the results came back negative.
into my second week i was still bleeding, very heavily, but no pain.
i went back to see a nurse she perscribed me UTOVLAN to stop my bleeding. ive been taking these tablets now for a week and nothing has changed, im still bleeding and heading into my fourth week. D.Bates