Lumbar EMG experiences?

I had a nerve conduction test done last Tuesday where they attach things to your legs and run an electrical pulse on it and measure the time it takes for the electrical pulse to get there. After the assistant had done the nerve conduction test, the neurologist came in and did an EMG test on me. The neurologist stuck a needle in my legs and then stuck a needle in my back. The EMG was painful for a split second but it wasnt until about 3 hours afterwards when I was sitting down at work that I started to feel almost unbearable pain. I can't get any answer back from the doctor about the test yet, so the best I could do was pay justanswer.com to ask them if its normal to experience pain after the EMG. Can anyone with experience with lumbar EMGs share an experience? How long does this feeling last? I really am questioning whether or not I should have gone through with the test. I am also told that EMG is very safe, however.