My doctor generally calls back when she gets the test results -- IF I'm not scheduled to come back in. Sounds like you were -- you said you had a follow-up appointment, so he probably is ready to go over them with you at that time. Besides, even if he DID give you the results of your evoked potential..then what? If there IS a problem, you'd still need to see the doctor to find out what needs to be done as a follow up (and there isn't much to be done with a "positive" evoked potential anyway..it more is an indicator of something wrong, not something that in itself needs "fixing".)
You remind me of that old prayer.. "Lord, give me patience, and GIVE IT TO ME NOW!!!!!"
No, you can't assume your results are normal. You can only assume that the doctor wants to talk with you IN PERSON about them, and you are scheduled for a follow-up exam, where it's likely he'll go through them with you then.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....