If you ALWAYS used condoms and are 100% sure there was no slippage or failures, then you never had a risk and never needed to test. Did you engage in risky sex with anyone else AFTER your encounter with the CSW?
Have you and your girlfriend been in a trusting & monogamous relationship this past year or so?
If YOU have not been with anyone else and your girlfriends two tests were negative, then you should let the guilt go as neither of you are HIV positive.
If you need further peace of mind, go ahead and test. It is EXTREMELY unlikely you will test positive, and I applaud you wanting to protect your girlfriend.
RubyWitch
Hello,
Protected sex is 100% safe.
If you had protected sex you are not warranted to get tested.
You are HIV negative.
Good luck and stay safe. :)