I was 25 weeks pregnant when I got married. It was a perfect day and I wouldn't change a thing.
Admittedly though, although I was the size of a house, I felt really well, and was last woman standing at 3am (being the only sober one helped!)
Depends what sort of wedding you're after, too. Mine was big but very informal - more like a big festival than anything else - so I wasn't under pressure to be "on show" all day. I was genuinely relaxed and enjoying myself.
Whereas if you're planning full-on tradition, with speeches, official photos, a first dance and all that jazz - lots of hanging about involved - I can see why you may not want to be pregnant and uncomfortable.
Honesty, if stuff like looking traditionally "beautiful" in the photos really matters to you, then put it on hold. I'm so happy and smiling in all my pictures, but am huge. That doesn't matter a bit to me, as neither did the fact I had to change into flat shoes by the evening as my feet hurt, but I know it would to some. I also didn't mind not having my "perfect" dress, but I know others might.
You just have to weigh it up really. What matters more, the "ideal" wedding or potentially not having another child?
I was in my 20s when I made the same decision - but decided waiting wasn't worth the risk, after seeing so many friends struggling with infertility. I got pregnant straight away, hence the huge wedding bump, but I know I was very, very lucky. I'd make the same decision again.
Statistically, six extra months or so is a long time to wait in your mid 30s, but you know that. You might be very lucky, you might not, but it really depends what's more important long-term.