Scary late periods

So my period was due two days ago and I have only had signs of tender breasts to give me hope that it will come. Me and my boyfriend of 2 years have never used a condom and only use the pull out method.. If I do not get my period in the next few days I'm going to take a pregnancy test, but I'm trying to figure out when would be the best time to tell my boyfriend if the test comes out positive? I'm 17 and he's 19