Does the spot look like a stain, but isn't? I have one of those, I've had it since the tooth grew in as a child. I forget what it is called, but it forms when the tooth develops and can be sensitive, but it isn't harmful. My dentist said if the pain isn't bad, there is no need to drill into it. But if it is unbearable, she could drill it out. I chose to let it be. Even before pulling,I would go months with no pain at all, but like you, I once made an appointment thinking I had a cavity because it hurt so much. After being reassured it wasn't a cavity, the pain went away a few weeks later. I can't pinpoint what exactly what triggers the pain to start, but it happens so infrequently, I don't worry about it. The dentists, of course recommend sensodyne toothpaste. And of course, if oil pulling helps you keep doing it.