most people develop antibodies within 3 weeks to 3 months, some might take up to 6 months.
I am not sure that you are on the right forum for this question but I will try to help. I have adopted a couple of children that were high risk for HIV so I had to have them both tested. They told me that we could not rule it out completely until they were 18months old. This is because you may not get the antibody for HIV for months. However, I think they now have a PCR test for HIV. It is much like the Hep C PCR test in that is test for the actual virus and I think you can have that done relatively fast after exposure. They will probabl;y still make you get tested for 6 months or so after.
Lots of luck. I am sure you are scared our prayers are with you.