Thanks for placing your query here.
I can appreciate your concerns.
If the boy is playful & active when not in fever & his oral intake is reasonable, you can wait for 2-3 days , since the most likely cause is viral fever
Keep giving meftal
& lots of fluids to drink.
If fever persist beyond 4-5 days ,please see a pediatrician
for check up & tests if required.
Giving antibiotic without knowing the source of infection is not a good idea.
Hope I have answered your query.
If you have any further questions I will be happy to help.
Wish him good health.