Confused PPD Test Interpretation

I am taking my pre-requisite for Nursing and PPD test is required. I did my ppd test 4 years ago and it's negative. I also did my chest-xray and it's negative.

Now the school requires a new ppd test. I am so worried because I have an induration of 8mm. I read all the articles and books about the interpretation of PPD test though they vary on the information. Some wrote less than 5 is negative and 5 above is positive. However, the induration should also be supported with the medical factors.

Example:

5 mm or more is positive in

• An HIV-positive person
  
• Persons with recent contacts with a TB patient
  
• Persons with nodular or fibrotic changes on chest X-ray consistent with old healed TB
  
• Patients with organ transplants, and other immunosuppressed patients
  

I am not HIV positive. I am currently tested.

I am not in recent contacts with a TB patient.

I am not working in nursing home.

I do not have nodular or fibrotic changes on chest X-ray.

I have current chest x-ray and its negative. Findings: Normal chest.

I do not have organ transplant.

BUT I have 8mm induration after 48 hours.

How do you interpret this?

Am I negative or positive in Skin TB Test?

Any advice? I am so worried about it because this might be a reason for hindering me in entering the Nursing program. Please advice me. Thanks.