Pregnant?

Hey y’all so I’ve been having sex with my man for about a month now and everything is pretty amazing, but I need some advice! So he’s had a vasectomy and we’ve been having unprotected sex because of it. I was supposed to get my period on the 1st and it’s been a couple of days but I still haven’t gotten it… should I wait like a week more and see what happens or should I get a pregnancy test?!?