Welcome to Healthcare magic.
After having so many tests negative including Elisa
and western blot you neednot worry but if you are so scared you may get a HIV
PCR test done for confirming .
Elisa is not a confirmatory test or specific test , hence the result indeterminate wil hold no value if western blot at the same time was negative.you need not repeat test so many times, ideally only after 6mths so that if a person is in the window period and tests negative, it can be confirmed after 6mths.
In your case, you have already completed 9mths , so most likely you are safe.