Can Taking 25mg Norethisterone Acetate Post Having Unprotected Sex Avoid Pregnancy?

Hi, I had unprotected sex on sunday 1st of march at 3 or 4 pm. I took 25 mg of norethisterone acetate (5 tablets each tablet 5 mg.) the next day (which is today, monday) at 5 pm. I cant find any emergency contraceptive in my country (I live in a country in the middle east where emergency contraceptives are not available). My last period was on friday 20th of february which means when i had sex it was on the 10th day of my menstrual cycle and I thought that the norethisterone will postpone ovulation. Am I going to be pregnant ? what else can I do or take? N.B: i m 20 years old and my period isnt regular already, it doesnt come every 28 days, sometimes it comes early and sometimes it is late that s why i m afraid i ll be ovulating that early.