Irregular shape of pectoral muscles - Muscular Strength

Why are my pecs shaped like this?

I've been struggling with an uneven chest and I'm not sure if it's

My left pectoral muscle is slightly bigger than my right pectoral

The 7 Most Important Exercises to Get Jacked and Build the Perfect

Sports Injury Bulletin - Diagnose & Treat - Uncommon injuries: Pec

Cable Exercises – how it helps to Build Muscle Strength

The 4 Best Stretches For A Strained Chest Muscle

Top 5 Unilateral Chest Exercises

Pectoral Exercises - Pec Exercises - Pectoral Strengthening

Muscle Specific Hypertrophy: Chest, Triceps, and Shoulders

Inner Chest Striations Exercises

Intercostal Muscle Strain