Hi. if i test for hiv five weeks after exposure at the lab will the tests be accurate?

Probably yes: First, you're unlikely to be at risk from such an event (unless the lab "exposure" was sex while you were there!). But if you were truly exposed, testing at 5 weeks is a bit early. The usual blood test (an HIV antigen-antibody, i.e. "4th generation") usually is positive by 4 weeks, but on rare occasions it takes 6 weeks.

If positive: If the result is positive, it is accurate. If negative, it would too early to rule out HIV. To be conservative you should get a HIV nucleic acid test done at 6 months after potential exposure if other results remain negative. Wish you good health!