Hi and thanks for the query, There is no air bubble in the nostril. What you have seen is probably your turbinates. Turbinates are normally present in your nose on both the sides. In the presence of nasal allergies they appear slightly bluish in colour. There is also a chance that you may have seen polyps in your nose. Polps are pale yellowish in colour and are filled with water like fluid. They are present in allergies of the nose. Polyps are quite common. Do not worry they can be treated easily. But you require an ENT examination to determine what structure you have seen. A painful lymph node suggests the presence of infection. The node that you have felt under your chin is very frequently enlarged in infections of the nose, sinuses and oral cavity. Nothing to worry about. Regards, Dr Kishori. Do not worry.