Hi I Had Unpretected Sex On The 7th Of August

Hi I had unpretected sex on the 7th of August I took the morning after pill the next day 5 days later I bleed for 1 day I was due my period on the 20th I'm like clock work every 28days but now I'm late I took a pregnancy test when I was 3 days late it said negative but I still haven't got my period yet and my stomach is bloated but no pains or any signs of my period coming could I still be pregnant will I wait another week and test again if I still haven't got my period