HIV DUO TEST ACCURACY???

On 14 August I had unprotected 3 minute anal sex with gay man. I was active and he was pasive. I took 4 hiv duo ag-at tests: 3, 17, 28, 35 days after exposure.All the tests were negative. My partner took oral fluid test at 8 days after exposure and hiv duo test at 24 day after exposure.Both tests were negative.I can t stop thiniking about it, searching internet, I can t eat. I have a girl and i did n have sex with her from 14. August because I am so scared of having HIV. The main problem is 3 months window period. I can t stop thinking is there any chance that i would be positive. Now is 7 week and i told my self that I will not go testing any more but times goes on and on and I am not sure anymore in anything. In many forums they say that duo test is accurate at 28 days 99.89 % ( I did it exactly on 28th and 35th day) and that there were no people who tested at 28 th negative become later positive. I am very scared and don t know any more who to believe....????? So my questions are:
1. If he is negative can I be positive?
2.Do I need more testing?
3. Is my HIV DUO test accurate at 28 and 35 days?
4.Can I have sex with my girl or I have to wait 3 months, test again and then be sure?
I know that I need a psyhological help but this anxity will destroy me...I can t stop thiniking about it....please help!!! For the first time in my life I don t know what to do and what is corect and which doctor can I trust!!!

[tomMulligan]

1. If he is negative can I be positive? - There's no way for you to be postive if your partner is neg.
2.Do I need more testing?  No. you dont have any risk.
3. Is my HIV DUO test accurate at 28 and 35 days? Any HIV test gives accurate result beyond the window period.
4. Yes you can.

[Teak]

Your 3 months post exposure test will give you a conclusive result. Have you taken an STD panel?