Spontaneous RE-fermentation?

I will admit, I have been putting this beer off slightly. I have a stout that has been in promise for about a month. All bubbling had ceased about a week ago and the krauzen had completely fallen out. I came home from work this morning and heard bloop bloop bloop, which I usually love to hear. Come to find out, I have a light layer of co2 foam on top and the airlock has a constant 3 second bubble.

I haven't taken a gravity sample since I pitched the yeast, but I would imagine it is hit its FG. It actually hasn't been opened since the pitch,so I am not thinking infection.

Just curious what others think. Happen to anyone else? Should I be worried? I was planning on bottling soon. I'm guessing I now need to wait longer and make sure my gravity isn't continuously dropping so they don't blow up.

Has it warmed up at all? It could be off-gassing absorbed co2.

I was actually just talking to the LHBS owner about this...this is normally caused by a wild yeast/bacteria getting in your beer and fermenting down lower than what the yeast you used should go. might still be tasty, but this is what I believe it to be.

With no information on your beer it could be anything. Bubbles are just off gassing- could be cold fermentor warming up, continued fermentation that slowed for a while, infection. Not opening is no guarantee of no infection. Only way to tell is take a gravity reading, taste it, and take another in a few days to see if it is changing. When at final gravity, bottle and see how it turns out.