I had it too. My dentist told me that some teeth that were filled may “wake up” and it hurts for a while (a couple of weeks or so). There’s really nothing you can do about it. He advised me to take motrin. Also, it MAY be it’s because of stress. I have a habit to grind my teeth when I’m under stress. Perhaps you do the same. If so, try concentrating on your teeth when your under stress (ok I know this sounds pretty goofy, but it does help!)and tell yourself NOT to grind ur teeth!! Oh, of course try getting rid of the stress inducer if that’s possible.
Hope u feel better soon!