Yup, give it a little time. Also, while you wait do a quick search for yeast starters. The liquid packs don't usually have enough yeast to really ferment a beer, even though they say they are pitchable. Its generally better to grow up a small batch (1-2L) of beer with your yeast, then pitch the yeast that grew up there. Its probably just that you underpitched a little so its going to take a little longer to get going.
Also, don't worry about the smack pack. All the little nutrient packet is is some wort and yeast nutrient. Breaking the packet just gives enough sugars for the yeast to convert some to CO2, swelling the pack. Its more a test of viability than actually doing anything helpful to your yeast. If the yeast was cold, they probably weren't active enough to ferment the little bit of wort, but were probably still viable. The other nice thing about starters is you can test the viability in there too and make sure they're going to work for you before pitching them.