oooh Kelly exciting that you're getting some prelabour startings!! Don't stress about ur OB being away, sometimes preLabour can come and go for a while, he may still make it back from holidays before the boys come!
I totally agree with Bella to try not to worry about the pain. Yes, there will be pain, but just take it one contraction at a time when it happens, breathe slowly, have some pain management techniques ready (massage, heat packs etc), and remember - marathon runners go through pain too but they get passed it because there is a greater goal in mind...how much greater is giving birth - to TWO babies! WOOHOO! Your body is perfectly designed to give birth and you will be surprised at the amazing things that you can do!! *HUGS* We're cheering for you!!