HIV testing after 9 months

Hi, welcome to the ehealth forum and I am glad to help you.
You seem to be concerned if the HIV testing is not able to detect the infection 9 months after the risk exposure.
No test is 100% sensitive and none is 100% specific either but still in HIV testing when the tests are repeated , sensitivity approaches 100% though actually never reaching 100%. For all practical purposes it seems highly unlikely that you cannot detect HIV infection after 9 months of risk exposure. If a test result is negative at 9 months well beyond the window period of HIV taken to be 3 months, you can, for all practical purposes, say that person is not infected with HIV.
Postexposure prophylaxis with antiretroviral drugs has been shown to lower the risk of seroconversion following occupational exposure to HIV by 81%, but has not yet been evaluated following sexual exposure. Though scientific data are limited, victims of sexual assault should be given the best information available to make an informed decision regarding postexposure prophylaxis. When the choice is made to take medications to prevent HIV infection, treatment should be initiated as soon as possible, but no later than 72 hours following the assault, and should be continued for 28 days.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.