I am 28 weeks and started my childbirthing class a couple of weeks ago. I would start looking for one now because sometimes they can be hard to get into!! Good Luck!!!
It's a good idea to sign up in advance just incase they fill up, but you want to do the classes close to birth so it's all fresh in your memory. I signed up around 23 weeks and the classes started at 32 weeks.
I think that you can take the childbirth classes up to 35 weeks. I had them and they were great!
This is my third baby and I'm JUST NOW going to my first Childbirth class. I didn't take the class with my first two. This time I want to try more natural and less invasive ways to bring my baby into the world so I think I will benefit from the class.
I made my appointment around 23-24 weeks. But when I actually take the class I'll be around 32 weeks, I think.
I'm doing the speedy class on one day, instead of spreading it out over 6 evenings.
I took my class at 30 weeks. Highly recommended, especially if they offer them at the hospital or center where you will have the baby.