Early and light

El

What are reasons a period would come 5 days early (when it’s always been either on time or up to three days late—it’s never been early and I’m in my mid 20’s with 12 years of having periods) and also be super light?

I am actually experiencing very low stress; and have actually been eating, sleeping, and exercising better for the past three months. Why is my body shorting my cycle by 5 days? That’s only 24 days.