Most lower OG beers will finish fermenting in 36-48 hours, but sometimes go as long as 4-5 days. I've had some beers ferment out overnight, but usually it takes about 48 hours for an OG of under 1.040.
The beer is fine. Now that fermentation is finished, the yeast will go back and digest less preferable foods, like their own waste products- so even though it seems like nothing is happening, there is still activity going on.
Wait about 10 days or so, and by then the beer should be clear (or clearing) and ready to bottle.