Strange period this month

Hi, I'm new here.. We've very recently started trying, have an 8 year old already, and have had 2 pregnancy so I'm pretty well versed in getting pregnant.. my partner isn't my child's father, were trying for his first. Last period before this month was 8/3 and we tried the week or so of ovulation that I'm tracking on my app.. my next period should have been today, usual length between is 27/28 days but this month I was 4 days early and heavy heavy for 24 hours.. barley bleeding from sat night to today.. not sure what or why my period could be like this they're usually very consistent. Any thoughts? Ty x