Hello,
Skin manifestations of HIV don’t come so early. This purple blotch can be a small bruise on the area. Many people do not develop symptoms after they first get infected with HIV. Others have a flu-like illness within several days to weeks after exposure to the virus. If you are apprehensive about the status of HIV, confirmation can be done by specific tests for HIV like western blot,PCR and ELISA.These tests may show accuracy after 6 weeks to 6 months as HIV antibodies take time to develop in the body.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.