If you are questioning your gravity, then I say rock out a reading at see what it says. Couldn't hurt. And it will give you a better idea on how much more time you should give it.
Also, and this is just a side note because I got in trouble with this as well when I first started, don't measure your fermentation by the amount of bubbles or airlock activity. Many things can cause them such as a slight temperature change to a small jostling when you walk past the fermentor. When in doubt-o trust the hydro (or refractometer-o)