Period was short

My period only lasted 3 days. That never happens. I spotted for 3 days then on day 4 it was extremely heavy and day 5 was medium heavy on day 6 which was yesterday it was brown and today it’s just brown spotting. The reason why I say it only lasted 3 days it’s because I bled like a normal period for 2 days then it was brown on the third day. Does anyone know about this ? My periods always last 6-7 days.