I was diagnosed after vng tests with central vertigo on my left side and peripheral vertigo on the right. Could this be a false reading?

Repeat testing? Although it is possible but unusual to have 2 different mechanisms for the vertigo, I think the tests should be repeated just to be sure since it may affect the treatment plans.
VNG vertigo test. Yes it is always possible that a test will give a false positive reading. That is it will indicate disease when there is none. Tests can also give a false negative test.That is it will be negative in the presence of disease. Only your team doing the test can help with this or get a second test to see if the tests are still the same.