HIV test results recorded three months after exposure are not conclusive. The final results are determined by analyzing other important factors such as the lifestyle of an individual and the time interval between the tests, according to About.com.
The results are conclusive only if an individual has not been involved in high-risk activity such as having unprotected sex with an infected person in between the testing period, states AIDS.gov. Due to the varying rate of seroconversion in people living with the HIV virus, it is advisable to retest six months after the last exposure. The six-month period is considered the maximum time required by the HIV virus to appear in the test.