Well it depends on the species of gourami. I know you can't be talking about kissers as they don't build a bubble nest so I'm guessing you have dwarf gouramies? If so, you probably only have males anyway. You may very well have had a bubblenest built but many males will blow bubbles just for the sake of it and it doesn't always mean the fish have spawned or that they are going to breed. It is usualy, however, a sign that they are content with their environment and feel comfortable enough to raise their own fry. So what kind of gouramies do you have? How many and of what sex? (If you don't know, post pics).