i had it pretty heavy, all the symptoms as by the book, but two independent labs showed that i didn't have dengue. so now i do not know if i had it or something different with very similar symptoms
afaik, Chikungunya and Zika can be very similar to Dengue.
False negatives are common when testing on the first week of symptoms. But after 1-2 weeks serology testing is accurate. My 1st exam was negative and the 2nd (after 2 weeks) was positive. There are other viruses with symptoms similar to Dengue like Zika and Chikungunya.