Period sex

So on my first day of period things escalated with my bf and we had unprotected sex. It was like 1min only and we didnt continue anymore. Im usualy a 30 day cycle girl sometimes 27 sometimes 24 so idk if i would ovulate early

That happened on the first day of my period and my period lasted for 5 days. What are the chances of getting pregnant?? Im worried about it. Please be nice im usually careful but this was this one instance we weren’t careful.