lizzie - i was in this situation with dd2
DONT worry. unless you have an unusual labour, itll be hours from when the contractions start to when you actually have to go in, and deliver your baby
is it possible that you could phone someone when your contractions start, and they could come and collect dd?
i remember calling my mother, telling her my contractions had started, she said she could be there in 4 hrs to collect dd1 (i had to keep my cool, not panic, 4 hrs sounded like ages!) but i didnt have dd2 til 12 hrs later
or have you a good neighbour? dh could stay with dd til the very last minute, ie the hospital could call dh when they think you dont have very long at all and dd could stay with a neighbour (or the neighbour could sit in your house if its nighttime)
its very very difficult but these things usually have a way of working themselves out
and you wont be in hospital for as long since its your 2nd baby, but dont rush home, have a good rest first
good luck! x