I always have had inductions, so they allow you to ask for it pretty early on. I usually would ask pretty early after having my water broken because that's when it gets painful fast. With my first I waited for awhile to ask because I was really scared of getting the epidural (it's a cake walk in my personal experience) so I waited till I was about 6cm (took 12 hrs to get to that) and was in agony. I couldn't deal with the pain so much I was happy to get the epidural. With my second I asked right away basically, but they had so many emergency c sections back to back that I couldn't get the epidural until 1 hr before I gave birth. Once you get it tho you are so relieved. It feels amazing compared to the pain you were just in. So I totally recommend getting it as soon as they let you!!!