Is Spotting And Bleeding While On Marvelon Concerning?

Hi, i have been having my periods for 2 weeks (heavy)from the 16 dec till the 30 dec 2010. I have a case of epilepsy on dec 29 and was given Norethisterone 5mg to stop my periods that stop on 31dec. I was started on Marvelon (21days pack)on 3rd Jan 2011. i had little spotting on 6 jan 2011 and started bleeding on the 7thjan while i'm still taking the Marvelon tablets. Can you tell me what i should do?pls help.