Welcome to the forum.
The sexual exposure is irrelevant at this point. Regardless of how risky an exposure is, a negative HIV antibody test 8 weeks after the last possible exposure is proof against a new HIV infection; even your 4 week test was 90-95% reliable. Even though many official sources say to wait 3 months, it really isn't necessary (see
http://www.medhelp.org/posts/HIV-Prevention/-A-Question-on-Testing/show/1347755). No physician who understands HIV would have requrested a viral load test in this circumstance. It will be negative and was a waste of money in view of the antibody test results. (Did you select your own tests from an online service?)
Anyway, you had a low risk exposure, since most sexually active women don't have HIV, few people lie about it when asked directly, and the average HIV transmission risk from unprotected vaginal sex -- for an uncircumcised male with an infected female partner -- is around 1 in 1,000. But as already noted, even if you had had the highest imaginable risk, the test results rule. You don't have HIV.
No further testing is necessary, unless the official advice about 3 month testing makes you decide to have a final antibody test at that time because another negative result will help you move on. But it's truly unnecessary from a risk assessment standpoint.
Regards-- HHH, MD