Will Discontinuing Contraceptive Pills Cause Delay In Periods?

Hi! i am a 31 year old, 5'1 (50kgs), was taking a contraceptive pill since the past few months, bt discontinued it as i felt bloated. I havent taken it for a month now but unfortunately had unprotected sex. Not sure when my period is due as i hear that period cycle may get disturbed once pills r discontinued. I might be on the 4th week of my cycle ...so shall i take an i-pill or restart my contraceptive ? plz help