mamabear……...since catechism classes are important for your son....and it would be a shame for a kid to be kicked out of a church function because of something that the parent had done.....I would take him to cathechism classes and let his father pick him up....(making sure that the teacher has husband's cell phone number)……
This is in the best interest of the child, as the first priority.....and it will reduce your worry about him getting there, on time, as the next priority.
If the child is supposed to go to the father earlier 9 thirty A. M.....I would say that he doesn't get the child until eleven A/M....when the class is over....
That is how I see it, but, of course, I am not in your shoes....