Had a root canal on tooth 5. First few days OK. Then there was some pain along the side of the gum, running along the length of the tooth. Dentist took xray, no infection. But it especially hurt when pressing on the gum with a finger. I can actually feel the contour of one of the roots on the outside of the gum above the tooth. The pain subsided a bit, but has come back a little over the past 2 days. Especially at the tip of the root (again, I can feel the contour). There is no pus, no pimple, and no sensitivity to biting. Any ideas?