How Accurate Is A Blood Test For Herpes? I Went

How accurate is a blood test for herpes? I went to the doctor becuase of an irritation on my genital area. It was just a very very small sore. The doctor looked at it and said.... "Yes, that is herpes. I'm 90% sure, but we will still take a blood test to have a second opinion" so I waited about three days for the results to come back, when I already came to the conclusion that I was doomed. And then BOOM negative blood text. I was a 0.00-0.90. I asked the doctor what it was then, and he said it could have been an ingrown hair or something... I'm just still skeptical about it because he seemed so positive that he knew what he was talking about. I need some reassurance that the results were accurate.

Thanks,
Shannon