Well, you should see rigorous air lock activity by tomorrow if you pitched two packs of yeast - that is if you're measurements were correct. However, from another of your recent posts you cleared up one point some of us have been wondering about. You clarified that you did indeed have airlock activity for a couple of days. In all honesty (despite the fact that some would say airlock activity is irrelevant as an indicator of fermentation) if your airlock was bubbling then the beer was fermenting. So I am at a loss as to why, despite obvious signs of fermentation, your gravity was the same. If I was a betting man -and I am - I'd say you misread your gravity. And if your beer is fermented out you may not have much in the way of fermentation happening.
Re=pitching the yeast won't hurt you beer - but it would be good to get this cleared up before your next brew.
I have a favor to ask - if you haven't yet pitched the yeast please take a gravity reading. If you can post a picture of the hydrometer and your impression of the gravity. Then we can check to see if you are reading it right. I don't mean to insult you but I'll admit that it took two brews for me to figure out which of all those numbers to pay attention to!
Prost!