Continuous Blood Flow, Mid-cycle Bleeding After Intake Of I-pill. Negative Pregnancy Test. What Is The Cause?

I took an ipill on 13 may 2012 due to unprotected sex on 12th. I had my normal periods on 5th may. After the ipill, I had periods from 19th may( less flow but lasted 7 days). And then again from June 9th (heavy flow).i started menstruating again from 24th June till 29th. In between these two periods, I also experienced slight spotting. On 30th, I had protected sex and the very next day from 31st onwards I have been menstruating till date. It doesnot seem to stop. I met a doctor last week and she asked me to do a pregnancy test at home and just wait for the ipill to get out of the system if the test results are negative. It was negative but I m really tensed with this daily flow of blood .