Growth spurt or reflux

I don't know what's going on with my baby this week. He will be 7 weeks tomorrow. For the past week he has been cluster feeding, sounding congested, and sleeping in short spurts. I know he has reflux, we just uped his Zantac, but the cluster feeding is confusing. He wants to eat snacks (BF) every 1.5 hours then he naps for about 30 minutes.