I think it may help if we ease your fears a bit about birth and labor.
But apparently I still have a few days to wait ... or hours ... it's really unclear how long pre-labor pains last before labor actually starts.
Forgive me if you already know all of this.
A full birth happens anywhere between 37 weeks and 42 weeks. It is very rare for a woman to actually deliver on her due date as that is just an estimated guess. Braxton hicks are false labor pains but once early labor pain start, you generally deliver within 48 hours although that is not a hard fast rule, it generally the case.
If you feel the pain more in your back, ask someone to turn the baby. Nurses can do this, but generally only if asked. Back labor is more painful.
Have they said how much you have dilated? The pain you experienced earlier was probably very productive. If you dilated that is most likely going to make your labor easier and shorter. I highly doubt that you are going to experience a significant increase from the pain you have already experienced. What will be different is that the pain will get closer and closer together so you will have less time for recovery in between the pain. Do not fear the pain of pushing the baby out. That was my mistake, I fear worse pain than I had already experienced.
The fear made the labor pains worse. Pushing the baby out is actually a huge relief and feels pretty much painless because of the pain you just experienced with contractions.
I know you are scared but I really don't expect you feel a measurable amount more of pain that you have already experienced. Your body knows what it is doing. A lot of things during labor are set up for the Dr.s and nurses convenience such as when to push, (seriously follow your body's lead and not the dr.s on this one) and what position they have you in. If you need to change positions do it. For me, being on my hands and knees gave me the most pain relief. If you need to get up and walk, insist on it.