Old root canal tooth suddenly tender to bite on — can it settle on its own?

I have a root-canal-treated tooth that is around 10 years old and has never had a crown.
On Sunday, after eating some very chewy/sticky sweet dates, I noticed the tooth becoming tender when biting/pressing on it. There is no throbbing or spontaneous pain, no swelling, and the gum doesn’t particularly hurt.

Over the next few days I unfortunately kept checking it by biting, tapping it, touching it with my tongue, and using salt water, which seemed to make it more irritated. Cold water also made the area feel sore temporarily.

I think it is less tender than it was earlier in the week, and salt water no longer seems to bother it much. It’s mainly sore if I deliberately press on one particular area.
I’m 36 weeks pregnant, so I’m very anxious about having an X-ray, and I’m also scared because I previously had another root-canal-treated tooth that developed very similar bite pain. That tooth eventually had to be retreated, although they couldn’t initially find an obvious reason for the pain.

Has anyone had an old root-canal tooth become tender to bite on and then settle completely without retreatment? How long did it take?