HIV Test Accuracy at 8 weeks

I'm very confused. I had protected vaginal intercourse and received very, very brief unprotected oral sex with a CSW. To give me piece of mind, I got tested for HIV at 8 weeks because I was told that would be completely accurate and the test came back negative. Recently, I've experienced chronic sore throats and I read that is a symptom of HIV, although I'm aware it's most likely not. I have 2 questions:

1.) I was tested 8 weeks after the incident to the day, however I was tested in the early afternoon and the encounter happened late in the evening, so I was tested 8-12 hours prior to 8 weeks exactly. Does that makes any difference whatsoever?

2.) Why do you say 8 weeks tests are 100% accurate when other sources claim nothing prior to 3 months is 100% accurate and in some cases, it can take up to 6 months for a test to become positive?

3.) Would it be a complete waste of time and money to get tested again as it has now been almost 6 months?

[imworried555]

you were never at risk of HIV, in the first place.