I think you will find that your teeth will feel extremely rooted in your gums quickly. You might be getting used to the whole sensation. Some people react extremely quickly, while others take quite a while to see or feel anything.
Are you swishing too fast? Perhaps it's the oil you are using? If you are using coconut oil, that is a very powerful oil...it tastes so good that it doesn't seem it should be so strong. Many people have experienced powerful healing reactions with coconut.
Perhaps you should change oil for a bit and see if a new oil causes the same reaction?