I asked pretty much the exact same question last year 4feb14... You've made me feel not so silly now lol
Anyway yeah I kept using the ergo with ds2 in front or back carry for months at the start of pg. Then I had a few months where I just didn't use it at all for some reason and then I did again in back carry when I was 8-9mths pg, that was surprisingly comfortable and I was annoyed with myself for carrying him around on my hip for so long!

Excellent, thanks!
I am going to start carrying her on my back. I bet she'll love it, plus I imagine it is easier on me that way (rather than the front) plus she'll be able to see more.