Back to the obs today, and complained about pelvic pain. I was instantly diagnosed with pubic symphysitis. This is basically an inflammation of the joint in the pubic bone, apparently pretty common in pregnancy. The treatment is to avoid walking, stairs, and any number of other activity, added to wearing a belt which essentially holds the pelvis together whenever activity can't be avoided.
I was shuffled off to a physio instantly, and being more careful about how I move does genuinely seem to be helping. The belt actually feels helpful when I put it on, so I imagine I will be a good girl and wear it when necessary.
On the plus side the obs tells me the baby is well down and is more than happy for me to go into labour as soon as we hit the magic 37 weeks. Apparently the baby is "a good size". She didn't comment on size for the other two, so this may be code for "huge". :)
I'm thinking 2nd November is a perfectly good birthday...
As a post script to the ophthalmologist stuff, the obs is fascinated by the whole thing, and thinks I should have the MRI - mostly for her curiosity I think. :)