Heavy bleeding after taking Unwanted 72.

Hello, I had my last period on Sep7th and lasted for 8days and on Sep18th i had unprotected sex with my bf and i had taken unwanted72 within 8hours and on Sep23rd &24th i had little spotting in red color and on Sep25th,26th,27th i had bleeding like where it filled only half of my pad. And from Sep28th to Oct2nd i just had little spitting again in dark brown color and suddenly on Oct 3rd it started like periods with stomach pain and its bleeding like normal periods infact a heavy bleeding even now. So iam confused whether it is my normal periods or the withdrawal bleeding. Please tell me if there is any chance of pregnancy and please let me know if this is normal to bleed like this..or shall i take any tablet to stop this bleeding. Thanks in advance.