If i get tested for hiv 8 weeks after exposure and i already had primary infection symptoms 47 days after exposure, is reliable?

Completely reliable: First, primary HIV symptoms always start by10-15 days. Symptoms starting at 47 days are not due to HIV from that exposure. Second, all currently standard HIV blood tests, i.e. newer antibody tests ("3rd generation") or antigen-antibody tests ("4th generation") are conclusive at 8 weeks. Assuming no exposure more recently, you don't have HIV.