Hi, Thank you for sharing your story. From your description of your possible exposure, there is of course a chance of transmission as even though you say he did not ejaculate inside of you, HIV and other STIs can be transmissible through pre-cum. Saying this, there is a possibility that your sexual partner is not HIV positive. But of course, if you are having unprotected sex with a partner of an unknown status, it would be advised to test yourself, not only for HIV. Since your possible exposure was around 4 weeks ago, if you are really anxious and worried about your status, I would recommend to visit a GUM clinic to get tested. You can use a BioSure self test to check your status at 4 weeks, but you would need to retest at 12 weeks for a conclusive result. I hope this information helps, if you have any other questions or require any more information, please feel free to leave them below. Kindest regards, Becky, BioSURE UK LTD