Hi,
Firstly, the instant test may not be completely relied upon. Get the standard
ELISA testing done for
HIV detection, in a standard laboratory.
Secondly, individual responses to the HIV tests vary depending on the
viral load, the antibody titers in the blood, the specificity and the sensitivity of the test used.
Thirdly, let us talk only about you in this instance. You have been faithful to your boyfriend, and you have tested negative before that.
It is possible that your boyfriend has had a false negative test or that you have had a false positive test.
Whatever the concern, please get the HIV ELISA test done at a laboratory. Get your boyfriend re-tested as well.
You may go in for more confirmatory tests like Western blot or even NAAT or even P 24 antigen assays.
Wish you good luck.
Take care!