Six weeks post exposure and then if that test is negative retest at 3 months to obtain a conclusive test result.
It was my first time actualy.. should I do the test now (2-3 days after relation) or later?
Most people are either honest when asked straight out, or you can tell if they are unsure or hiding something. Of course, that should never be a reason to have unprotected sex with someone (does not apply to your case).
If you haven't been tested recently, it is a good time to do so anyway!
Thank you for your advice, she didn't seemed worried or anything and I think I can trust her.
While your overall chances of having caught HIV are low...you still need to be tested, as you had an exposure. Really, an exposure is an exposure.
Test at 6 weeks post the exposure...this result will not be conclusive, but if you are anxious about it, it will help you to relax a bit as a 6 week negative result is an excellent indication of the final result. Then, test again at 12 weeks post the exposure for your conclusive result.
And, while testing for HIV....have a basic STD panel done, to cover all of the possibilities. Diseases like Herpes, and others...are WAAAAY more common and easier to transmit than HIV.
Hang in there...you will likely be just fine...but you have to test to be sure.