should I go get rechecked?

A couple months ago I was told I had an STI after having a painful/itchy sensation in the lady bits and took the antibiotics and just figured it was all good to go. 
Lately I've been having a little bit of pain and itching sensation again - should I go back to get rechecked? 
I haven't had any sexual activity since the original diagnosis, but have continued to use the same menstrual cup as I assumed it would be okay as it as nonporous. 
Just checking before I go spend money on tight funds!