Twin - my paps are always painful, and it is not unusual, it can depend a lot on the position of your cervix. Apparantly mine is quite high and tilted a bit further than usual bit towards my back so it makes it hard to get at.

I haven't experienced a vag labour yet, but O wouldn't worry, I would say the two are not connected at all, one is something going in, the other is something coming out! And coming out with the help of muscles and hormones and mucus and all sorts of other things that help it along.