Since you noted that symptoms don't mean anything you don't need an answer to the fact you are wasting your time studying "symptoms."
The ONLY thing you need to figure is how long was her test after her last sex with her BF - which is the only thing you omitted, so please provide.
If she didn't wait long enough she could have HIV so in that case, it doesn't prove anything that you take tests because she can pass it on to you at any time down the road. If it was long enough to be conclusive, she couldn't have HIV.