How To Test For HIV?

Hello, I was in a sexual relation with my classmate during which I had uprotected sex with him twice, so I went for a hiv tridot test at 11.5 weeks after I last had unprotected sex and oral with him it came out to be negative. I have been reading on the web that conclusive tests would be after 3 months and some say after 6 months im really in anxiety. I would be again going for a test but still im very worried. I didnt knew about the sexual health of that boy. Please help.