Hypnobabies accidentally play ahead?

Ash • Be Kind.
Has anyone accidentally listened ahead during hypno sessions in the hypnobabies program? I fell asleep during one and I have no idea how many I ran through. I felt great though! 
Are there any negatives to this? The program book is pretty insistent about going in order and I don't have any teacher in my area to ask. I have no idea what was covered... Only my subconscious would know.