I was going to say the same thing Kris - one of my friends was told the same by their doc and his little girl ended up with pnemonia.
Having said that, Rachael - the fact she is throwing up the phlem is a good thing. This means her body is getting rid of it and it isn't sitting on the chest. It is when things sit on the chest too long that complications occur. How long has the cold been going on now? If she is still throwing up Monday - I would go back to the doc (make an appointment now and then cancel it if you don't need it). If at any time over the weekend you feel it is getting worse - go back. You will hear the gunk on her chest because it is there at the moment. It should clear up though. They will be reluctant to prescribe antibiotics because his body is shifting the phlem on its own at the moment.

HTH and hang in there.

MG