Hi again Jess,
No you won't need an EKG unless it's for a routine medical. The worse side effects of the tricyclics are such things as sedation and dry mouth etc, you may have noticed. The tricyclics are more dangerous in the overdose scenario than the SSRI's eg:Lexapro.
Your 25mg dose is standard dose for pain relief. Adverse reactions can happen sometimes so If you notice any irregular heart rhythm/breathing problems seek medical help.
Look after yourself
Nick