Dengue IgG positive means that in past you had dengue fever.
Your platelets are fine.
Repeat a platelet count to check it's trend.
Some case of dengue may be missed by these tests. So need to follow platelet and PCV reports.
If you have any queries you may consult directly using chat now option.
For more information you may read my article on dengue fever.
Next Steps
"Dengue Fever : Don't Panic, Know How to Deal With It" by Pratyush kumar mishra -
https://www.practo.com/healthfeed/dengue-fever-don-t-panic-know-how-to-deal-with-it-29261/post