There is a lot of confusion when discussing HIV symptoms because the ARS (initial acute infection) and long term advanced HIV disease are two very different things.
ARS is highly variable but typically starts 2-3 weeks after exposure, lasts 1-2 weeks and sometimes longer, and from what I've gleamed from the experts usually involves a fever (typically high and "noticeable" I hear) along with sore throat and sometimes a rash and generalized lymph node swelling in neck, armpits, and groins. Oral manifestations however are not generally part of ARS (despite some internet websites symptoms lists).
Oral thrush and leukoplakia are two oral symptoms that are seen in people with advanced HIV disease and from what I hear are hard to mistake (thrush being painful and leukoplakia being impossible to "scrape" off.) I believe by this point people are generally pretty sick and have other things to worry about than these.
If you are in the Army I can tell you from experience that you have been tested for HIV - atleast at MEPPS prior to basic training or in any SRP prior to a deployment. This pretty well rules out long term stages of HIV disease and therefore any worry about oral symptoms.
Hope this helps and take care - Matt