Greetings, I can understand your concern.
There are fair chances that your tooth or gum is infected.
As you mentioned, your tooth has been capped.
For the accurate diagnosis, an x-ray is mandatory.
If you need any further help then you can consult me on practo. All your queries will be solved.
Regards:Dr Akash Bhagat
The Dentist's Office
Next Steps
please visit a dental clinic and get a radiograph done for the concerned tooth.
Health Tips
avoid self diagnosis