How long after you stopped taking the pill did your monthly's return? I stopped taking mine 6 and a half weeks ago and still haven't had a period. I stopped taking it because of a clear blue digital saying 'pregnant 1-2'. All other tests (different brands) since have been negative so I can only assume that positive was due to a faulty test. I was reading up on my pill and the majority of people's periods resume after 3-4 weeks.
For me and my sister, after we stopped taking the pill our periods returned regular 3-4 weeks. This can probably be different for everyone though and if you are worried you could pop in to see your GP? They'll be able to do a pregnancy test too if need be. X