Hi . It is clear you have concerns and it is good that you are seeking information. I need to stress that we are not medical professionals and, for your safety cannot give medical advice or diagnostics over the internet. I do want to share with you this article from our editorial team on PEP, including the guidance that "PEP needs to be started within three days (72 hours) of the exposure; the sooner the medication is started, the better it is at protecting you. PEP works the most effectively if it can be started within 24 hours of exposure, if possible:" https://h-i-v.net/pep. In addition, the various government health information resources, such as this one from the National Institute of Health, provide the same timeline: https://hivinfo.nih.gov/understanding-hiv/fact-sheets/post-exposure-prophylaxis-pep. I have not seen any information on whether PEP taken after 72 hours delays seroconversion. Is there a medical provider you trust to speak with about these issues and testing? I also want to stress that this is a community of people who understand and have a wealth of information about living a long and healthy life with HIV - please feel free, if you like, to ask additional questions or need any support. Best, Richard (Team Member)