Thanks everyone! currently enjoying some skin to skin cuddles while he sleeps, looking like butter wouldn't melt. It wasn't this peaceful between 3am and 6am when it was DH's turn to sleep!! 
I started getting contractions about 12 hours after the sweep. They were 2-3 mins apart after a couple of hours, and stayed that regular for about 4 hours. The hospital asked me to go in to be checked as I had to start antibiotics asap in labour. They were very regular but weren't very strong so I was reluctant we were going in too early, sure enough they sent me home again- as soon as I got to hospital the contractions pretty much stopped. Back to 2 mins apart as soon as we got home (white coat syndrome!!) so back to hospital a few hours later. They examined me and I was 5cm, then things suddenly ramped up and he was born half an hour later... we didn't even get the bags out of the car!! No time for antibiotics even, never mind water or any other pain relief- luckily I had gas and air which did nothing for the pain but did a fine job of giving me an out of body experience So in the end things were a bit of a whirlwind!
Hope everyone else with new babies is getting into the swing of things!