Hi, My Period Was Expected On November 21 2016 But

hi, my period was expected on november 21 2016 but i took nerothisterone to delay it because i was going for a holiday to a different timezone,4 days after i took the morning after pill and on 28th november i travelled back to my country, on 30th to 4th december i got very light bleeding and till date i havent got my periods yet, should i be worried?about pregnancy or any complications?