How accurate is 7% chance of pregnancy?

Jess • 👨‍👩‍👧27 years old. Wife. Momma. Girl #2 due Nov '23🤰 👼🏼 2/28/19 ♥️ 3/28/20 👼🏼

I just finished what I think was my period and I logged everything appropriately but my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> app is telling me there’s a 7% chance I’m pregnant. I know that’s low but curiosity just has me asking how that is suppose to work?