I tested negative after I performed unprotected oral on a female. It was 16-20 weeks after my exposure. What worries me is that I think I may have lost some weight during this time. Like 5-8 pounds. Can I consider my test conclusive and move on?

You can be pretty sure that your test was fine but before you move on a few things to think about. First as far as loosing the weight, that can be from the stress or being worried. You need to relax, take a deep breath and think about the fear that you just had. Please protect yourself in the future. The chances of getting HIV from you performing oral on a woman in pretty slim. But don't make it a habit to do that to everyone because you can still get herpes that way. But if you decided to continue pleasing us women make sure you don't have any open soars in your mouth because that will increase your risk some.