I Took Tetanus Shot From Local Chemist. Two Days Later

I took tetanus shot from local chemist. Two days later felt swell lymph node in groin. Went to doctor, did fnac test. Result was. NO MALIGANCY, NO AFB, NO GRANULOMA. REACTIVE HYPERPLASIA OF LYMPH NODE. Not sexually active but still done 5th week hiv1/2&p24 ag cmia test from dr Lal path labs. Result non reactive. Now my question is I am not getting the reason behind my swell lymph node in groin. Doc told me not to worry. It's 3 months now. Lymph node is very tiny now. I can feel it. Any suggestion? Do I need to worry?