Thank you for your question.
The HIV test spoken about is a test which uses colour bands to determine if a test is positive or negative for the HIV antigen. A control band appears to confirm that the test strip is working correctly and that the result band if positive has not appeared by error. If there is just the control band and the test band does not appear it means the test is negative ie the sample used does not contain HIV.
The test should be repeated after three months as there is a window period following infection when the test can be negative but the person continues to harbour the infection. Please discuss with your doctor to clarify your doubts.