Congratulations!
I have mine, but that's for my classes.
Keep in mind, that for September due date, June and July start would be best, and April and May is a bit too early - since you have to practice evey day until the birth day, after you finish the course.
I know that some moms find that OK, and there are some that don't have enough patience towards the end...
There is a way of listening to some CD's (Affirmations) now, and then starting the course in a month or two.
You'll enjoy it, either way!