Hello, you were at risk, but your risk wasn't the highest, unprotected insertive vaginal sex has around 1 in 2000 chances of transmitting HIV, if the receptive partner is HIV positive, off course, and yours was very brief, that plays in your favor but testing is advised in your case.
About tests, 3rd Elisa gen will give you an excellent indicator about your status around 6 - 8 weeks after exposure and 4th gen 4 - 6 weeks after exposure. A result given in those times is very unlike to change, but only a doctor, based on your risk level and his experience could advice you to skip a confirmatory test after 12 weeks post exposure.
thank you for your prompt responce. i went to that lady again and asked about her health condition, and she told she absolutely OK (i know it doesn't work).
Am thinking to take her for checkup instead me wait for 4 weeks. Please advise.
also i forget to share with you i have urinated after the ejaculation and cleaned throughly.