Need some answers please!

I was fertile 5-11. My bf and i had sex on the 5&6th, he also ejaculated in me both those days.  I am 6 days late for my period. Two days ago i took a test and it said it was negative. I guess it could be stress also making my period late, bc i was thinking if i was prego or not. Im kinda hoping i am. Im jus a little confused on how i cant be pregnant if my bf ejaculated in me both times.