meg, hun only about 15% of labours start with waters breaking. both of mine were artificially ruptured just before delivery. the sac makes it easier to push too. I really hope your labour is not so fast that u don't make it to the hospy. We only used our ambo cover after Em was born coz she was so sick and ended up in hospy for 10 days and i had no access to the car when we needed to take her in to the hospy.