I had both my children unmedicated so pushing came natural. The doctors did not have to tell me when to push because my body did it on it's own. I'm not sure how the epideral would affect the pushing. I do know the doctors have to tell you when to push as they monitor your contractions.
I had an epi but it was completely gone by the time I got to pushing. This was my experience as well. You'll push because you won't be able to to NOT push. And the medical personnel will monitor it and give suggestions if needed.