Can I still be pregnant if I haven’t had sex since my last period?

I had protected sex last month, and my period came (a normal period which lasted about 5-6 days) after this. I haven’t had sex since my period, however I’m now one day late. Is it possible I could be pregnant or is it something else making my period late? I’ve been very stressed this past month and I know that can affect your period, so I was just wondering.

Advice please!