Have you taken a sample and seen in the gravity has dropped any (hydrometer reading)? Two days with one pack of yeast, no starter and that high of a starting gravity makes sense that you are getting a longer lag time.
Many like to use this site and it's always been accurate as far as I can tell: http://www.mrmalty.com/calc/calc.html
as it will tell you how much yeast needs to be pitched per batch. According to that site you will need three packs without a starter and two with a starter. That high of a starting gravity will stress just one pack of yeast. I make larger starters with more yeast and a stir plate for higher gravity batches.
Regarding the pack not inflating much, are you sure the smack pack is broken inside, and how long did you let it sit? I've had a few packs that didn't inflate much after a day of sitting out but still were fine when in the starter or pitched directly in the wort.