Hi Rahul! It can still likely be a flu. Fever, body aches, malaise, headache, loss of appetite etc. are typical symptoms of viral fever.
It usually takes 5-7 days for viral fever/flu to go.
Drink plenty of water, eat healthy food, take Calpol as required.
Next Steps
If need more information, consult online
Health Tips
Since the tests were done immediately, sometimes if fever persists before 5-7 days or have some unusual symptoms or if condition worsens, repeat tests and some additional tests are required