Doctor i have been sleeping with my girl friend ...

Dear Customer
Welcome, and thank you for trusting us
Regarding what you mentioned, the history of sexual intercourse without using a condom , so this carries a risk of getting sexual transmitted diseases STDs such as HIV.

I do HIV test after the history of that unprotected sexual intercourse and it was negative ?

Yes this can make the possibility of the infection less likely .

The sexual partner is tested positive for HIV ?

In this situation you have to repeat the HIV tests such as combo test in order to rule out the possibility of infection.

What should I do in this case?

You have to visit your GP doctor so that the doctor could do a full clinical evaluation of your case then he will treat it accordingly.
  Stay well.   
Feel free to message me anytime here if you have further questions.
It is our pleasure to help. Please feel free to reach out to me anytime.
You can also ask our other certified experts in various fields such as Nutritionists, Lawyers, IT Experts, Therapists, Mechanics, Doctors, Handymen, and more.
Kind Regards