I don't know why people are such naysayers. I think they feel they're being judged for their choices (whether it's getting an epidural, sceduling a c-section, etc.).
When I was pregnant the first time, people were always telling me how awful x, y, z was going to be, and that I'd change my mind...and you know, I didn't change my mind. I had the unmedicated birth I wanted. I went home 3 hours after delivery, and went on to BF my babe for almost 2 years, and raised her vegetarian, vax-free, and in cloth dipes til she potty trained, etc, etc.
It sounds like you're doing what you need to do to prepare for the birth you want. Don't let the neg-vibers get you down. I just learned to smile and say, Well, we'll see. I'm pretty determined to do x, y, z." People that know me well know I'm stubborn and won't change my mind once it's set!
I find even this time around, people are like "So, are you going to have another freaky all natural birth, you big granopla eating hippie?" so vent away! I feel your pain.