Greetings!
Firstly - I understand that you are and educated and a well informed girl; Please understand that unprotected oral or vaginal intercourse has its risks of transmission of sexually transmitted diseases. Also there may be a risk of unwanted pregnancy. So please take adequate barrier precautions.
Secondly - the photos are not very clear, however,it is less likely to be like
HIV acute rash! But it is highly advisable that you see a qualified dermatologist near you and frankly discuss your issues with him or her and also get screened for STDs. Hope this helps, Warm regards, Dr Govind Suresh Mittal, Bengaluru