I wanted to know when can you tell when the nerve in your tooth is repaired?

Never does: The nerve never really repairs itself. There are only a finite number of cells in the 'nerve' and when a certain number have died, the remaining cells die.

Concur: I agree with dr. Doyan's excellent answer. If you have issues with the nerve of a tooth, no meds will "cure" it. The infected tooth material must be removed. If infection has reached the pulp chamber of the tooth, seeing a root canal specialist, an endodontist, would be prudent. Ask your dentist for advice.

Regenerative endo: Dr doyon is correct however in recent years there has been advances using stem cells to regenerate pulp tissue in teeth. It's only done by endodontists.