Back 🙄

I promised myself I wasn’t even going to log back on for a few months I even deleted my period apps, and as soon as I was starting to find peace my body goes all wacky....I’m on cd 8 and my period was lighter and shorter than usual. It’s usually 5-6 days but this time it was 4 days and now 4 days later I’m having mild period like cramps back cramps and tmi but having brown bloody discharge. Last night it was creamy but today it’s very snotty. I don’t usually O until CD 16. What could this be ?