Welcome to the forum. Thanks for your question.
The brief reply you had on the community forum was officially correct -- i.e. the HIV antibody test manufacturers and standard advice from public health agencies is that testing is not conclusive until 3 months. However, that's outdated advice, for two reasons. First, the modern antibody tests are almost always positive by 6 weeks; it rarely if ever takes 3 months. Second, combination testing -- for both HIV antibody and the virus itself (by either antigen or nucleic acid amplification test, or NAAT) -- is 100% conclusive by 4 weeks after the last exposure. Below is a thread that discusses the apparent discrepancy between standard advice for testing at 3 months and the current scientific realities:
http://www.medhelp.org/posts/show/1704700
I have the impression you're a bit surprised at your negative test. I'm not. Even after two years, many partners remain uninfected. It depends largely on what your sexual practices usually are (anal, oral, mutual masturbation, etc), his HIV viral load, and other factors. I'll be happy to comment further on this if you'd like to describe some of these details, beyond the fact that you're usually not the sexual "receiver".
My advice is that you see a doctor or clinic with substantial experience in HIV diagnosis, if you haven't done so already. With the right tests, you can have a 95% reliable result as soon as 10-14 days after your last sexual contact with your partner and 100% conclusive testing at 4 weeks. (Because of the offical advice, many experts would also recommend a final antibody test at 3 months -- but that would be icing on the cake, strictly for reassurance.)
Best wishes-- HHH, MD