No worries here. Test results always are more reliable than symptoms in judging whether someone has HIV, because the symptoms of HIV are highly variable. Even the classical and highly typical symptoms of HIV or AIDS are more commonly caused by other conditions. And you don't have such symptoms anyway. Mouth ulcers can occur in people with HIV, but only in those with advanced disease, i.e. overt AIDS -- usually after several years, and always in people who have many other symptoms and generally are very ill. With modern HIV tests, it never takes 9 months for the result to become positive; you didn't need testing any later than 8 weeks after your Thailand exposure, or 3 months at most.
I am skeptical about a "weak immune system" as a cause of oral ulcers. However, it seems clear your dentist has not been able to make a specific diagnosis and you need to move toward a more expert opinion. You don't say where you are, but if in the US, and especially near major metropolitan areas, you should be able to find an oral medicine specialist, especially in connection with a dental school or major medical centers. Oral Medicine is a subspecialty of dentistry and your dentist should be able to make a referral. Alternatively, see your primary care provider and/or an otolaryngologist (i.e., ear, nose, throat specialist, or ENT).
In the meantime, you can relax about HIV as the cause. That has been ruled out by your negative test results.
I hope this helps. Best wishes-- HHH, MD
Thank you Sir for the advice as I have had trouble understanding what is happening to me. The test results have helped me but an advice from someone like you will add to that help.
In regards to testing is thier any documented case of a person turning +ve after the 6 months mark?
And is Is thier any sub type that the tests are known to miss? becuase while going throw the archives on this site a saw some people talking about diffrent Sub types What exactlly is deffrent between them? do they make you turn +ve in defrent time intervals or are they all the same?
To sum up I understand that you would not advice me to test again and even if i did test you would expect a _ve result again?
You are over-thinking this and spending too much time on line looking for bad news to confirm your fears. Please re-read my reply, which explains several reasons -- not just your negative test results -- that you don't have HIV. As to the actual cause of your symptoms, I don't have any good ideas and in any case figuring out the cause of problems other than HIV and STDs in off topic for this forum. I gave you advice above about how to go about learning the cause. There is nothing more this forum can do for you.