From what i've heard it's meant to be a really positive experience I haven't come across one person yet who said it didn't work eben in a little way for them.
I just posted in 3rd tri that I'm trying my new CD out for the first time, i've just woken up from it and had to come on staright away to how good it was.
Didin't think it was working then next thing I know I wake up with no idea how long i've been asleep for and the CD not even playing anymore!!
I did a hypnobirthing course, and although I had a C-Section (my baby was breech) there is absolutely no way I'd have been able to go through with it without general anasthetic if it hadn't been for the techniques I'd learnt. This is the book -
https://www.amazon.co.uk/Hypnobirth...=sr_1_2?ie=UTF8&s=books&qid=1278621447&sr=8-2
...I think that one comes with the CD. If you google 'hypnobirthing' you'll be able to find a practitioner in your area. They are quite pricey, but IMO it is certainly worth it!
if you fell asleep you havent done it right you need to be able to stay awake to get benefit
if it is sending you to sleep do when more awake and in a more appropriate situation sittign on a birth ball for example not likely to fall asleep then