Well, when you think about the anatomical aspects of the birth process, it's no mystery why it is painful. Think about it, things are stretching nearly to their limit down there. Your body is having these intensely powerful contractions- they have to be intense so the baby starts to move downward, a 7lb baby isn't going to slip out all by itself, It's going to take some hard work. While birth is painful, it's nothing to be afraid of.
All mammals give birth and expect for humans, all of them do it unmedicated. Perhaps their labors are shorter, more intense, perhaps not. Point is everything experiences pain when it brings forth a new life, it is natural. This is something I took comfort in knowing when I gave birth to my first child in 2007. Now that I am expecting again and have experienced the real pain of birth, I still do not fear it. I know my body has a job to do and will get it done. I also know that if I need it, I can manage my pain with a medication.
I did not and will not get an epidural, because I feel it interferes with the necessary sensations down below. While I was having excruciating back labor with my first, I only elected for an epithecal shot. This worked because it kept things from hurting down below in terms of feeling tearing pain, but it let me feel what I was doing. The back labor pain did not seemed dulled much at all by the epithecal, but in the end I was still glad I chose it to help me.
When it came time to push, there was no greater reassurance that things were going properly than me being able to feel the baby moving downward. I knew I was making progress and that gave me the confidence to keep going. I'll never forget how strange a sensation when the baby's head came out- everything felt all rubbery down there and then suddenly, the pressure was eased. Having a more mild pain med than the epidural may work for you, that way you can also feel what needs to be done. A bonus to a non-epidural birth is pushing is usually shorter. My son came out in 45 minutes.
So mom's to be, I'm not going to lie to you. Birth IS painful, it has to be, it's natural. Don't fear the pain, it is just a symptom of your body working hard. Talk to your doctor about using meds or not and be comfortable in your decision. I will say that birth is an actual good pain. At the end there is a baby.