2000 Nissan Maxima Loose Clutch

I have noticed a difference in my Nissan Maxima 2000. All of a sudden, today my clutch has been much looser than normally...For instance, when I press down on it to switch gears, it is much easier to push down (Almost too easy to press). My clutch has been replaced about 6 months ago so it is relatively new. I was wondering, is there a way to tighten the clutch? or something else? what should I do? My car does drive but the clutch just does not seem right.