The only true"Signs of fermentation" come from your hydrometer, NOT AIRLOCK BUBBLING!!!
over 50% of my beers never have a bubble, it is normal actually for some not to bubble...
That's why we say you should never use a cheap chinese plastic airlock as a "fermentation Gauge," it's not...It's an airlock, nothing more, a VALVE to release excess CO2, to keep from blowing the lid off the fermentor...If it's not bubbling that just means that there's not enough CO2 to climb out of the airlock, or the CO2 is just forming a nice cushion on top of the beer like it's supposed to, or the airlock is askew, or it is leaking out the cheap rubber grommet, or you have a leak in the bucket seal...all those are fine...if CO2 is getting out then nothing's getting in....
That's why we recommend to new brewers to use their hydrometers, not their eyes. I believe MOST of the new brewer's "stuck fermentation threads are not, stuk, they are using the airlock as a "gauge" rather than checking gravity.
I have found that oldschool S types seem more reliable than the 3 piece to actually bubble. I think maybe co2 isn't always heavy enough to push up that plastic piece in the center of the 3 piece.
Read this...
http://blogs.homebrewtalk.com/Revvy/Think_evaluation_before_action/
Your beer is fine...just walk away for 10 days minimum then take a hydro reading...
Don't "fix" something that probably ain't broken...in other words don't add anything to your beer...take a hydro after 10 days...