Bleeding around time period was supposed to come

last month I had unprotected sex during my fertile period and then bled like my period about two weeks later, this month I didn’t have sex and my period is almost a week late which it never is that late. Is there anyway that I’m pregnant? I know that you can’t be pregnant if you get your period obviously, but my grandmother had what seemed to be her period for three months while she was pregnant with my aunt, so I just wanted to see if any other women who have had similar experiences could shed light on this.