NR may have only just given them confirmed timings. Most tour operators only send out tickets when NR confirm the route and timings, so I'd reckon the tickets ought to be with you early next week.
But as Phoenix says, if the ticket hasn't arrived then take some ID with you to prove who you are and they'll have records of who's booked with them and find you on their boards. Of course, a quick call to them if it hasn't arrived by Thursday would probably be a good idea, just to be 100% sure.