baby sounds congested

Jackie • 24 y/o Jake G 💍 mama to LNG 4/21/17 👶💙. SAHM . Idgaf about your opinion. It doesn't phase me🙌I say whats on my mind. Gtfo my page if your a hater. I don't need that type of drama. Stay blessed . 🙏🏻
After every feeding and when we try to burp our 6 week old son he sounds congested. 
Also he doesn't burp at all. What could be causing baby to sound congested? We feed him 2-3oz every 2.5-3 hrs