Can i be pregnant?

I had sex 1 week ago and I'm suppose to start my period tomorrow.. i haven't had any cramping as i usually do 4 days before my period. My boyfriends sister had a dream that their mom (who has passed) came to her in a dream giving her baby hangers and saying "take care of jaime, take care of jaime", which is my boyfriend. When his sister has dreams with their mom in it it always comes true..

Other than my little story I was just wondering, even though I had sex 1 week ago, would I still start my period tomorrow or will it not come?