Does going off the pill throw off your period?

My girlfriend just stopped taking the pill a few weeks ago, and she has not had her period yet and she is about 5 days late. I was wondering if going off the pill messes up your cycle and would cause you to be this late. Would it completely throw off the cycle and make it so she could have a period at and given time? I have heard that you cant base your period time off of when you were on the pill, as to when you are NOT on the pill. Anyone know if she could be late because she is off? And if so, how late could it possibly get up to?|||YES IT DOES MAKE YOUR PERIOD LATE.|||Yes, it is possible. Do not at any time have unprotected sex if you don't want a baby. If you want one, what r u waiting 4?|||yes i does she may stop getting it 1 day if she kepps taking it|||yes the pill does effect ur periods when u go off them nothing to worry about if it is late for another couple of days i would speak to a doctor but there shouldnt be anything to worry about :)