First of all Good luck! Take a deep breath and relax. Your body knows what to do.
I found that swimming was REALLY theraputic for me during the last trimester. It will help with your joints because it will help to drain your lymphatic system of extra fluid. Drink a big glass of water before you get in the pool and one afterward. You may have to get out and pee a couple of times but it is worth it. Swimming also simulates zero gravity, so you won't feel pregnant while in the water. I used to have to feel my bulging tummy to make sure I was still pregnant LOL.
Your feeling of 'forgetting something' may be your nesting instinct setting in which means you are closer than you think! I have a friend that had a compulsion to get out and trim the hedges the day that she went into labor!
In terms of preparation right now it is about mental preparation. You need to relax and quiet yourself and visualize how you will cope with pain mentally and physically. Do you think you will internalize tune everything out and take a hot bath, or get up and go for a walk or bake cookies? Everyone deals differently, and you will find your way ...deep in your soul you know it already. Embrace that knowing. Remember that there are no expectations to live up to with your labor because it will be YOUR labor.
I had a home birth and there could have been the biggest new years eve party going on in the same room and I don't think I would have noticed.
If you can find the book 'The Bradley Experience' I found a really good labor pose in there that I found was really helpful for relaxing through contractions. My mom kept asking me if I was falling asleep. Duh! But seriously the single biggest suggestion I can give you is as you feel a contraction coming on to concentrate on relaxing every muscle in your body (this is not a simple task and requires your concentration). That way you are not fighting against what your body knows to do naturally which is push the baby out. Fighting your contractions will lengthen your labor.
And remember there is one sure thing...ALL babies come out one way or another.