Please explain what significance the viral load has. If I have an undetectable viral load does it mean I would test neg, or does it mean that I am not contagious during unprotected sex. How does it affect whether I get OI's or not. Which is worse a high viral load or low cd4 count and which would cause me to get a serious illness?

A viral load tells you how much HIV is in your blood. Period. It doesn't tell you how much HIV is in your body, because there is plenty of virus in tissue, which isn't measured by a blood test. Susceptibility to OIs is a function of CD4 cells, not viral load, although people with very high viral loads may experience more immune dterioration. It's not easy to say which is worse, because they mean different things. But in the short term, it is your CD4 cells that will keep you from getting OIs; over the long term, it is also good to have your HIV be as controlled as possible in order to limit HIV disease progression. I hope that makes sense.