Should I worry?

LO is 5 weeks old and sick. He's had a slight cough and he's stuffy/ there's phlegm that you can hear. No fever, no trouble breathing, plenty of wet diapers. He's vomited twice but each time he ate a lot right before doing so.
I called his pedi and the nurse sounded extremely worried and they're having me bring him in today.
He's had this since yesterday and now I'm beating myself up because apparently this is a lot more serious than I thought.

Quoting Mom2William&Michael:" LO is 5 weeks old and sick. He's had a slight cough and he's stuffy/ there's phlegm that you can hear. ... [snip!] ... He's had this since yesterday and now I'm beating myself up because apparently this is a lot more serious than I thought."

I would worry, but I'm a worry wart  
Did you take him in yet? Any updates? Hope he's okay!

Quoting Ryleigh's Mommy ♥:" I would worry, but I'm a worry wart   Did you take him in yet? Any updates? Hope he's okay!"

I took him in. He has a head cold but they're afraid it could get worse.