Your chances of getting shingles increases as you age, but that certainly does not mean that young people cannot get it. In fact, when I was in 7th or 8th grade, I remember one of my fellow students having it. The only reason that older people get it more is because their immune system is weaker, so they can't fight it as much.
The same goes for HIV. People with HIV are more likely to get shingles because they cannot fight it. However, there are many things other than old age and HIV that can cause your immune system to be weakened.
"Your immune system is the part of your body that fights off infections. Age can affect your immune system. So can an HIV infection, cancer, cancer drugs, radiation treatments, or organ transplant. Even stress or a cold can weaken your immune system for a short time and put you at risk for shingles."
http://www.niapublications.org/agepages/sh
ingles.asp
So you can't read too much into the shingles thing. However, you also can't read too much into the fact that you don't have HIV symptoms. Many people live symptom-free for years and have no symptoms at all when they test positive.
You'll just have to wait for the results and try not to worry about the symptoms. You certainly cannot diagnose yourself by symptoms or assume that you are safe because of the lack thereof.
