My advice is just to relax and roll with the punches! He should have followed up - that's a really long time to just assume it's going to get to you. Here in the USA, they say 4-6 weeks. If you haven't gotten it by the longest time, you call immediately. It's the government, afterall
Relax! Try not to worry about the stressful other people. At the end of the day, your HUSBAND and kids are going to be there. You've done everything in your power to make it easy for people to go. Don't feel bad if people screwed it up for themselves - you'll miss them if they don't go, but do NOT let them ruin your wedding day!
So excited for your wedding - it's going to be amazing!!