Well, with that OG, even with two smack packs, you underpitched. If you had 100% viability in each smack pack, you still would need about 3 packs without a starter, according to http://www.mrmalty.com/calc/calc.html
. And your viability was probably significantly less than 100%, unless the yeast was brand new. If you can get more yeast, you may want to pitch another pack or two. Odds are, you'll start seeing activity soon, but your yeast are going to be stressed. Next time, I would suggest making a starter.
What are you fermenting in? If it's a bucket, pop the top and take a look. It may be fermenting without seeing airlock activity if the lid is not sealing perfectly.