Will herpes virus show within a week in blood test if you have an outbreak at the time of that test?

Not usually: On the assumption that you are talking about herpes simplex virus, type i or type ii, then blood tests are rarely done and are almost always negative. The virus, once you have it, lives in nerve cells in sensory ganglia and an 'outbreak ' occurs when the virus multiplies, travels down the nerve axons to the skin (or, in the case of type ii, the genitalia) and produces skin vesicles.