How Should Microgynon Be Continued After Missing A Dose?

Hi, I have been taking Microgynon for a number of years.....I had my period as usual in December however I forgot to take the pill again for a few day after the 7 day break and therefore didn t bother to take the pill at all, my next period started on the usual day however it was exceedingly heavy, after about 2 weeks of bleeding (I started back the pill on the usual day) I saw my doctor and he prescribed norethisterone, he advised that I should stop taking the Microgynon and to take the norethistherone only. Those pills are now done and I was unsure as to when I should restart the Microgynon. Help!