What does this mean?

Mackenzie • One in heaven 👼🏻 One in my arms 🌈💙 One in my belly!

I’ve normally had a 5-7 day long period every 28ish days but the past 3 months its only lasted 2 days and then completely stops and it’s been about every 30-32 days. I’ve had a very regular period since i first got it 8 years ago. Why the sudden change? Not on any form of birth control but sexually active with my fiancé. Has this happened to anyone else?