I Am Diabetic Type 2. I Take Glucophage Twice A

I am diabetic type 2. I take glucophage twice a day at 500 mg. I usually range after supper around 185. I just checked it because I was feeling strange. I checked my level and it was 345. I took the glucophage about 20 minutes ago. It has never been this high. The only difference was that I had an epidural block done for pain at the l4. & l5 region. Should I wait a little while and recheck or go to the Emergency Room?