It would be of interest to know exactly what test was used, and
also some details about your symptoms. If you had a positive culture
for HSV, the diagnosis probably is solid. But certain other tests are unreliable, especially examination of scrapings under the microscope, called a "Tzanck test". You might check with your GP about it. If there is any doubt, then a repeat blood test should be done in 3 months, with the expectation it will have turned positive.