What Causes Delay In Periods While On Qlaira Pills?

Hello. I was on Qlaira for 1 1/2 years, but a month ago, after I finished my blister, I decided to stop taking it (didn't start a new one when I was supposed to; january 29) its been over a month now and I still haven't gotten my period(last period date: started january 28-ended january 30/31) Last time I had unprotected sex while on Qlaira was around pill number 15-17 . I've heard about post pill amenorrhea but I don't want any surprises. Should I be worried?