early period

Good morning guys

I'm a bit confused and stressed right now. According to the period prediction( which has been spot on the last 4 months) predicted I would start my period in 2 weeks and I started today. When I logged that in, it changed my ovulation prediction for the previous month which ment we didn't have sex as much since we thought it was the follow week. What does it mean when you get your period EARLY? On average, how many days after your period do most ovulate?