Hi there,
The best and most accurate time to get a test for HSV-1 is to wait until a sore appears, and get that sore swabbed for HSV as soon as possible (withint 3 days). Blood tests for herpes are not routinely done, but they are accurate 12 to 16 weeks after an exposure. The trouble is that a positive blood test will not tell you where on your body you have been exposed, and many people test positive because they caught oral herpes in childhood.
Hope that helps,
Health Nurse