This Month, My Period Arrived Late And Was Very Short

This month, my period arrived late and was very short - 2 days of heavy bleeding (bright red blood) and then completely stopped, not even any spotting. My periods can be irregular, but I have never had one shorter than 5 days and it's 7 days 90% of the time. I have had unprotected sex this month around my ovulation time. Is it normal for a period to go so short suddenly?