How conclusive are HSV tests (both culture and blood tests)?

Its a long story so get ready....Four years ago I had a blood test done for STDs and it came back positive for HSV-2. About half a year later I went to another clinic and got a second opinion with another blood test and it came back negative. A couple weeks ago a lesion formed on my chin, which I initially thought was a pimple, but was not healing with blemish treatment and began to spread and became filled with fluid. When I was younger I had shingles so I thought they may have been it. I went to the clinic and got a culture test done and the result came back positive for HSV-2. I can only wonder if I go back to get a blood test if that will come back negative! I read that the blood test are less accurate than the cultures...is that true? Also, is it possible to have HSV-2 on your face?