The chances of acquiring HIV
occurs in 2 cases:
1. If your partner is affected with HIV
2. If there is any cut/raw surface in your oral mucosa
through which the infection can spread.
If the above mentioned criteria doesn't hold true for your case, then there is no need to worry about getting HIV.
There are certain tests like p24 assay or PCR for HIV, which becomes positive within a week and are almost 100 % sensitive.
Even the presence of a single virus in the body can be detected by PCR.
So, if this test comes negative, you can be sure that you are safe.
Wishing you a good health.