Tooth works

Well I was right, as usual, there is a root canal in my near future.
I went in early and they took an X-ray but saw nothing. The dentist did a freeze test on the tooth I was complaining about and nothing.
Next he decided to take an X-ray of the one above. I looked at him, quizzically?
"Sometimes the pain migrates"
Sure enough the upper tooth has an infection and a bad root.
I left with Vikiden and anti-biotics. Went to work and had an awful day.
Nine days left.