Question about root canal not needed

[JustPostingQuestion]

I had severe pain in my back tooth. Two dentists took xrays but couldn't really say if I needed root canal. I went to the root canal specialist and she wasn't sure. Then she said I probably need it on both. She filled me with novocain but I panicked because of the rubber dam. I'm going to go back when I am calm. But now the tooth is hardly bothering me. I'm wondering if I even need a root canal after all. She said I would because after the antibiotics stops working the pain will come back.

Here is my question. What will I or my insurance have to pay if I cancel all future appointments for this root canal. Will I be billed for the novocain and visit? It will get costly.
I'm not sure I needed it to begin with.