You could certainly retake the IgG test, yes and see if your values in particular have changes. You do have a higher than usual negative, but that may or may not have any meaning – hard to say without a follow up test. Herpes does present with blisters so it is possible that they symptoms that you describe are related to herpes. Without a swab test it is really not possible to say but I can say that it is concerning. However, most often herpes blisters do break in the normal situation.