Thank you, everyone, for all of your responses. I'm sorry it's taken me so long to get back to this one.
To answer the questions:
How did I feel about it? I do agree that it's not the ideal look, *but* there's a high that comes with taking a fashion risk and feeling like you pulled it off as well as it could be. You know? That's actually the spirit of this challenge-- to take the risk and have the confidence both. ;) The other part of it is that I don't think I could feel bad wearing that black pencil skirt-- it's awesome! (My second favorite maternity piece)
Was it comfortable/ did it stay tucked? It was comfortable. I did have to adjust the tucking a few times. The funny thing is that the part I was most concerned about-- the front where I literally had 1/2" of shirt to tuck-- stayed put. It was the back and back sides that poofed out as you noticed although I think in the picture it looked more pronounced simply because my arms were raised.
I doubt I'll do this look again, simply because I don't think I'll have enough shirt for tucking any more ;) but it was very fun. I hope to see others take up the challenge to take a risk.