There's so much confusing and conflicting information online that it's hard for people to understand what is correct. Many online doctors state 6 week antibody test won't change and some state 3 months. For the average person this is hard to take in. From what I've read online all UK gum clinics should be using 4th gen for there HIV testing.
That's good.
If they did a 4th gen hiv test at day 70, I would think they would consider you conclusively hiv negative.
If it was an antibody only test chances of it turning positive at week 12 would be "very" unlikely.
I just spoke to my clinic they said a blood test will check for everything and a urine sample will be checked for everything. She said it's a sexual clinic so everything gets tested for. She also stated that there is a 2 week window period for all STI/ STD.
Hiv symptoms do not occur on day 1 or 2.
You need to call the clinic and ask them what they looked for and whatever they looked for, is a 70 day negative a conclusive result.