I don't know what to do!

He went to the vet today and got some shots, and he's been fine all day. Now all of a sudden he threw up twice and both times there were worms in it! I didn't exactly...examine...the puke so I couldn't tell if there were multiple small worms or just one larger one in each puke pile, but there were worms nonetheless.

He seems to be ok now, but what should I do? It's 2 am and my vet isn't there tomorrow. Is he going to be ok? Can it wait until Monday? Do you think he is reacting to the shot? Ughhh my poor boy :(