would appear in more than a single location like the one you may have in your neck. Also, ARS (acute
retroviral syndrome, the name for acute
, symptomatic HIV
infection) almost always includes fever (usually quite high), sore throat, and skin rash, none of which you mention. (In fact, about 70% of people with ARS have all three -- rash, sore throat, fever.)
Therefore, it is unlikely your apparently enlarted lymph node is due to HIV.