Should I use a pregnancy test?

Patient: I had unprotected sex at the end of the month (August) and the end of the month is usually when I get my period and my period hasn’t come and it’already the 1st of September, should I take a pregnancy test? I also took a Plan B pill about 5 days after the unprotected sex so I don’t know if that would have anything to do with my period being late.

Symptoms: No symptoms