I had unprotected last night, my period was due today but it hasnt came.. When can i take a pregnancy test?

So, i had unprotected last night. (I know it was stupid so please no lecturing.) My period was due today, Its usually on time but last time it was a week late. My question is.. 1) Is it likely that iam pregnant? I heard its least likely the day before but why is this? And im also aware you can get pregnant at any time during the cycle.. and 2) When can i take a urinal pregnancy test? Like, in a week or so? What?