Pain in tooth after re-RCT first step.

How long does a tooth hurt after root canal with calcium hydroxide inside?I had a root canal on tooth46 more than an year ago since that tooth hurts for tapping and biting pressure on it. No changes even after the root canal.  Same symptoms.I have jaw pain under ear lobe area and neck for 1.5 years &this tooth was suspected as the cause of that pain. No relief&definite diagnosis yet.I went to new Endo and he spotted that first root canal is not filled till the end of the one root. And that dead space could be causing the symptoms and pain. I have constant pain in that tooth underneath and gum area. It hurts for any little pressure on it. Even pressing with fingers on it hurts. I have been told to retreat root canal. I had the first step done 2 days back. He reopened just that one canal and filled with medicine. The second treatment filling is after a month.It's been 2 days and still paining.tooth still hurts the same way as before.Is this normal to have pain after medicine or any issue