I Am A 26yrs Old Female, I Had Got My

I am a 26yrs old female, I had got my last periods on the 21st of june 2016, i had intercourse with ma fiance on the the 28th of june 2016 morning he did not ejaculate inside me.
But I've missed my periods for the month of july and august 2016 due to which i did the pregnancy test on 15th august 2016 which was negative
So i did the pregnancy test again on 25th august 2016 which again turned out to be negative.
I am extremely confused that am pregnant or not.