I get that. I was worried about it too. But it doesn't happen to everyone and I honestly have no idea if I pooped during my first birth. You probably won't know either. And I asked my husband the other day cause I didn't know and he couldn't even remember if I did. He watched the whole thing so he would have seen and he's definitely the type that would tell me if I did, but he really wasn't sure.
Im glad im not the only one worried about this
I've been told that it doesn't happen to everyone, but that it is unavoidable for others. You could try eating very small meals or ask for an enema when you get there. Honestly I just warned my partner that it happens and my mother obviously has three kids and they both reassured me that the baby is the only thing they care about and not to feel self conscious. You are making a miracle happen and this should be the least of your worries:)