My husband and kids have been possibly in contact with cold sore virus. i kissed them plenty of times over the years and recently just before a cold sore appeared. how accurate is herpes simplex virus antibody test two days after exposure?

At least half of all people acquire HSV1, so such exposures are nothing special or worrisome. The HSV blood test takes up to 12 weeks to become positive, and is never a way to diagnose newly acquired herpes. In a family situation like this, blood tests should not be necessary. If there are typical cold sore outbreaks, that's enough to be sure of the diagnosis. Or see a doctor for confirmation.

Your family likely has been exposed to your virus many times. More than half of the "normal" population has been infected with HSV 1 and the only manifestation they have are occasional cold sores. Testing for HSV 1 is not warranted.