Does a negative westernblot for hiv1&2 (as a screening test) @ 16weeks post exposure rule out hiv1&2 100%? do i need repeat test at 6 months? thanks!

Wrong test, too long: The HIV Western blot test is not intended for screening and could miss some infections. You need a 4th generation (duo, antigen-antibody) test, which is conclusive any time 4 weeks or more after exposure; or a 3rd gen antibody test at least 8 weeks after exposure. Nobody needs testing as long as 6 months; even 3 month is longer than needed with modern tests. Discuss with an NHS GUM clinic.