Coming off the pill

Does anyone know how long it takes your cycle to get back to normal after coming off the pill? I was on the mini pill so didnt have a period for a year but since coming off it I had one after 5 weeks then one after 2 weeks then another after 3 weeks! Now waiting to see if this next one comes soon (3weeks tomorrow) or goes back to 4 weeks as it was before I went on the pill . Just a bit worried as hoping nothing is wrong or when I should go and see a doctor. I stopped taking the pill 3 months ago nearly now