How people perceive the pain varies from one person to the next and one pregnancy to the next, but personally I'd be most apt to describe the pain as menstrual cramp like. They start off relatively mild and then they grow in intensity. It is important to remember that it is productive pain and that it WILL end! You just have to get through one contraction at a time.
I also don't think that your pre-labour pain threshold correlates well to a women's labour pain threshold. I am the type who cries over a sliver and managed to have a natural childbirth with my daughter. I did opt for narcotics with my first but there was factors involved there which did not make the situation ideal, mainly having absolutely no support. I also remember having one client who felt that pap smears were so painful that she was brought to tears when every she got one. She had wanted a natural birth but really felt that she wouldn't be able to take the pain and frankly throughout her entire pregnancy I doubted her ability as well

and guess what! She never even asked for pain meds once! She handled the labour beautifully and wonderfully and certainly taught me a lesson regarding assumptions!
But as mentioned above, I do think there are factors that influence how one copes with the labour pain, because it is a physical and mental work out.
Self-motivation is a big one. And you certainly seem very motivated!
Sleep is another big one. Women who are very sleep deprived tend not to cope as well. Sleep is definitly a difficult thing to achieve in late pregnancy but if you can get a chance to nap take it. And if you begin having contractions that are still spaced out quite abit (go by your care providers recommendations as to when to go to the hospital) do try to get some sleep or atleast lie down and rest.
As a midwifery student, in my practical placements I would always tell first time moms to page according to the 5-1-1 rule. That is getting contractions every five minutes, that each contraction lasts a minute and that pattern has gone on for an hour or page if they can't cope with the contractions. Just from personal experience I've noticed that if the contractions start in the night, the women who time 4 or so contractions and then goes back to sleep until they get stronger (You won't sleep through active labour) cope much better then the ones who spent the night awake timing the contractions for hours and hours anxiously awaiting true labour to begin. While it is hard to rid yourself of the excitement of getting so close to meeting your baby that rest is certainly worth it. Same goes if your water breaks. Speak to your health care professional about your next step (which will vary depending on individual circumstances) and then whether you wait at home or hospital for labour to begin do try to get some rest cause it won't be long till labour comes!
Keeping your energy up is another factor. Humans need food. It's their fuel, it's what creates our energy to do things. While many hospitals do not allow eating in active labour and frankly many mom's don't even want to bother eating at that point eating during early labour can be beneficial. I'd avoid big heavy greasy meals that wouldn't sit well but small nutritious snacks that are easy to digest are great.
Then there's the support around us. Women with a strong support network who believe in her innate ability to birth naturally tend to do well (though when things don't go as planned, they tend to be the ones who get most disappointed... something to watch out for). Having a careprovider supportive of natural birth is also beneficial... When your in pain it makes it very difficult to stay strong when someone offers you pain medication every 15 minutes.
The last factor I want to mention is labour progress. Labouring for 9 or 10 or 11 hours is hard work... When you double that time coping can become quite difficult.... Exhaustion and sleep deprivation start to kick in as well as the voice of concern from those around you making you doubt your own ability. While there are factors in labour progress that you have absolutely no control in, there are a few things you can do ahead of time to help. Getting baby into a good position before hand is a good start (see
www.spinningbabies.com), alternating positions and moving around in active labour is also a good thing to do. They don't completely eliminate the risk of slow labour progress but they can help.
It's also good to go into labour with a WIDE RANGE of different pain relief ideas and it's good to practice these beforehand. Some ideas include hydrotherapy (labouring in water offers wonderful pain relief, hypnotherapy, massage (teach your partner the absolutely lovely art of counterpressure and double hip squeezes - the book the birth partner is a wonderful resource), then there's the TENS machine which can also be very helpful. Have never used that personally but I hear it's wonderful.
Anyways, I hope I didn't scare you too much with all that and that maybe some of what I said will help you on your birthing journey!