Hi, how long has it been since you had the skin test done? It should be read after 48-72 hours. It should be read by a Clinical Laboratory Scientist, nurse or doctor. A positive is >= 10mm. But It should be read at the largest area across and it should be firm feeling or hard and dense. If it is just red then it is likely to be a reaction or something else. So they have to feel it. Have you had the BGG vaccine? If so that will cross react with the PPD skin test too. So a good secondary check would be to get the quantiferon gold blood test.
mkh9