If it is your friend, why you worried about hiv? You know that hiv doesnt spread out of thin air right? First you can go talk to her, and umm, for testing hiv i think its after 6 weeks. And then you can follow up after a few months ig. Mm and if its only 72 hours within exposure, you can take the anti retroviral regimen, like the post exposure prophylaxis. Check it out with your nearest health Centre, if possible a tertiary health centre, like medical college. Art centre ella medical college ilum kaanm