The test returned a “Not Detected” result for HIV. Antibodies to HIV Type 1 and Type 2, and the p24 antigen, were not detected.
A negative result on a 4th generation test performed at four weeks post-exposure is highly likely to exclude HIV infection.
To be as certain as possible it is highly recommended to be re-tested at three months post exposure.
A negative test result does not completely rule out the possibility of HIV infection. After exposure to HIV there is a period called seroconversion, during which the virus reproduces and the body produces antibodies to levels that become detectable in the blood. Samples taken in the very early (preseroconversion) phase or the late phase of HIV infection can occasionally produce negative findings. As yet unknown HIV variants could also lead to a negative HIV finding. In rare cases, seroconversion can take longer than normal.
For those who remain sexually active and/or are a part of a high-risk group, the recommendation is to have an HIV test every three months.
Testing can be done more frequently if there is potential HIV exposure. Sharing needles, lack of condom use during sex (especially anal sex), or a broken condom during sexual penetration are all reasons sometimes linked with possible HIV exposure.
Gardnerella Vaginalis 
