Hi. I Had Unprotected Sex With My Boyfriend And He

Hi. I had unprotected Sex with my boyfriend and he cum in me on wednesday 6th january 2016, getting back home at night i took salt and water because i had No pill at that time to take. The next day i had one tablet of postinor2. Later at 8:30pm. We had unprotected Sex and he still cum, i didnt take the second tablet until 5:30am the next day. Can postinor2 still be effective taking just 2tablets?.Its actually my first time of taking it and i saw my period on the 12th of Jan. Can i Stil be pregnant after that?