Drug tests are meant to detect THC and "immunoassay with antibodies that are made to detect it, and its main metabolite, 11-nor-delta9-caboxy-THC (THC-COOH)." The tests are not looking for other cannabinoids however it is technically possible if you had unsusually high levels of hemp oil you could potentially have a false positive. I would think that would be unlikely.
For instance you would need to take between 1000 to 2000 mg a day of hemp oil to ingest around 6mg of THC. Hemp actually contains THC but at such a low dosage it is not considered psychoactive. I would find it hard to believe you would be taking 1000mg of CBD oil as that is a lot!!!
I am not a doctor and this answer represents my opinion based on my research. I hope this helps.