No like Nad123 said, your Doctor will request specific tests, a CD4 count as well as a HIV viral load and according to that they can determine if you are HIV positive or negative as well as how bad the Virus is if it is positive and then together with the age, height and weight they will work out how much meds you have to take on a daily basis to keep the Virus under control.
No, it does not show up in routine blood test. A special test is used to detect presence of HIV antibodies in the blood after 4-12 weeks of exposure to HIV.