...and you're already having contractions, the baby is likely to come VERY quickly?!
I've just had DD3 and my midwife mentioned this to me at my last couple of appointments. We live 20-25 minutes drive from the hospital and she advised if you're having contractions and your waters break while you're still at home, you probably won't have time to make it to the hospital.
And she was right! We went to the hospital when contractions were 4-5 mins apart and I was only 5 cm on arrival. Ten minutes later my waters broke... ten minutes after that DD3 was born, to the surprise even of the midwife who delivered her!
I'm glad I was forewarned and thought I'd share this with anyone else expecting DC3.