I'm 2 weeks post-Tx and still taking my Percocet, Jim, about every four hours, like you. I couldn't do without it -- I'm still in plenty of pain to merit taking it! Don't worry about getting hooked at this point; no need to endure pain when you don't have to (that's what everybody tells me, anyway!). And you'll heal faster, too.
If you were taking it a month or more down the road, it might be a different story. For now, I wouldn't worry.