Dr. HHH is a US doctor and the DUO test was only approved June 2010.
http://www.fda.gov/downloads/BiologicsBloodVaccines/BloodBloodProducts/ApprovedProducts/LicensedProductsBLAs/BloodDonorScreening/InfectiousDisease/UCM216314.pdf
Page 27
An ARCHITECT HIV Ag/Ab Combo test result that is nonreactive does not exclude the possibility of exposure to or infection with HIV-1 and/or HIV-2. Nonreactive results in this assay for individuals with prior exposure to HIV-1 and/or HIV-2 may be due to antigen and antibody levels below the limit of detection of this assay.
UK Testing Guidelines
http://www.bhiva.org/documents/Guidelines/Testing/GlinesHIVTest08.pdf
Post testing
Page 11
The need for a repeat HIV test if still within the window period after a specific exposure should be
discussed. Although fourth generation tests shorten the time from exposure to seroconversion a repeat test
at three months is still recommended to definitively exclude HIV infection.
HIV DUO tests haven't been approved in the US for two years, so your information is incorrect.
I heard no one in last 2 year
And dr HHH said that he has never seen somebody test negative with HIV DUO test in 6 weeks, and than turn positive after 3 months