It's not low risk, it's literally no risk at all. As in, zero. You might as well worry about being pregnant because that's just as likely as you having HIV from what you did with that masseuse.
In answer to your question about testing, since you were never exposed and there is no exposure date, there is no conclusive timeframe. You can take a test anytime and it will be negative. There is no point in the future when it will be conclusive because there is no start date.
Thank you. Have alot of anxiety surrounding this incident which I'm in therapy dealing with. Was just testing because i thought seeing it in black and white on paper and the proper time is reassuring. Will take my neg result and move on. Thank you again.
If you are anxious, the right way to go about it is to see a therapist and not get placebo test.