And good luck to you if you guys get pregnant soon!
I have IBS-D, I'm not sure if you have C or D...
My stomach has been the same...well, for the first 12 weeks or so I had D EVERY morning. I'm so used to it though, it was no big deal. I was actually really happy because most pregnant woman have major C. So be glad if you're a D!!
I did go 23 days once being C, and I was MISERABLE. It was my own fault though, because I was eating everything you can imagine that is unsafe - donuts, fried foods, etc.
Even right now, I'm nearing the end of the 5th month, when most woman are really C, and I have been fine! In fact, I've been eating dairy this whole time with no problem - and diary was a huge trigger before I got pregnant.
SO - everyone is different, but I think most woman either stay the same, or get a little better when they are pregnant (as far as the tummy goes).