It could be. It just means that it is off gassing co2. Your fermentation might be finished. You will need to take gravity readings to be sure. I have seen bubbles in my airlock at 2+ months with a big beer in secondary.
What is the fermentation temp? At lower temps, the process will take longer. I often ferment in the mid 60's to keep the flavors clean. How many bubbles per minute? If it's only a couple, you may want to take a gravity reading.