If you had a negative LP and evoked potential that is very promising. Fatigue is a very natural part of pregnancy
. Are you sure you are having Lhermitte's? If I were you I would go back to the neurologist for another check up, with ms there will be other signs, such as hyper reflexes, positive Romberg test, Babinski's sign, bladder problems, as well as optic neuritis, is that the problem you were having with your eyes? Migraine headaches can cause similar white spots on an MRI.