+1 to what monty said. Checking volume won't do anything. There may be krausen that will rise, but other than that, the volume of your beer will be the same. I would say just leave it in the primary for at least 3 weeks. That is, unless you're going to dry hop. Then you can rack to secondary and dry hop for another 7-10 days. And still, that can be done in primary as well. Primary fermentation is done by the first 2 weeks, but the yeast still need to tidy up after themselves. Leaving it longer won't cause any harm, and actually you will be rewarded for your patience with GREAT BEER!
EDIT: Sorry. Internet's on the fritz, took too long to reply. So you're gravity hasn't changed in 2 weeks?????