I had unprotected sex twice, and my period has started 3 days early. what does that mean?

It means...: For a teen girl, it means it's time to stop having unprotected sex unless a couple is married, settled down, with stable jobs that offer health insurance (babies have many expensive doctor visit the first few years), and are ready and committed to raising children for the next 20 years. Yes, humans take at least 20 years to raise, from birth to college.