I can't remember mine, but I'd agree with RP. 10 minutes miling and no more till you're used to the distance, probably....
The old adage of start slowly and get slower springs to mind when you're in new territory. See how you feel first before you try to increase your speed. If 12 minute miles are what you can sustain, then stick to that!
When I first started going above 10 miles, I used to like a little snooze afterwards! I always got the mini LBs to make me a sandwich and run me a bath.
I still like the odd snooze.....