I am always getting paranoid about accidentally doubling up. In fact, that feeling happened to me tonight! I can definitely see how being on the safe side by skipping a dose would be less risky than taking too much. A pharmacist friend said missing one dose shouldn't make that much of a difference.

I took it though since I am 80% sure that I didn't double up.
Once I called a Pharmacist at CVS regarding this when I truly did think I doubled up. I had a little bit of a headache, but nothing extreme. I am on a dose of 400 mg (200 AM and 200 PM), so I was definitely worried about doubling up on such a high dose. Luckily, the Pharmacist said she couldn't find any extreme warnings for accidentally taking another 200 mg. She said some people take as much as 700 mg per day for seizures, so she said I should be ok, but just to be mindful of any unusual changes and not to take the morning dose until talking with the doctor. I still get nervous though.

I think you are wise for consulting with your Pharmacist. I would stick with their advice. You should be fine. I've skipped a dose here and there, and I felt better for doing so, as opposed to taking too much. Nothing major happened to me. I completely understand the anxiety.