What is it in at the moment?
By "no bubbles" do you mean through an airlock or no signs of activity at all?
If it's in a bucket then airlocks won't bubble if the gas pressure can escape through any small crack, so use your other senses. Look at it, is there any sign of froth on the top? Put your ear against the FV, can you hear it fizzing? Crack the lid, put your nose in and inhale, does it make you cough or go dizzy? Try not to cough into the bucket.
If "yes" to any of the above, then it's fermenting.