I would wait.

With number 2 you will find out about DDH much earlier - e.g. we had first indication DS ok at 6 weeks (not sure if you are finding out sex but if you are and is a boy the likelihood is much lower also), I also had very bad muscle separation and a heavy DS (4.5kg) so I did end up not baby wearing him as much as I might have hoped but think you would be fine until at least some indication on the hips. My motto is always wait and see with everything though.

Also there are wraps etc you can use to carry the little one on your back - I find with the stomach muscle thing like Hot I said the back carrying is far better than on the front. I went to ABA meet on babywearing a bit too late for me but showed lots of carrying for newborn on back (is great because don't get crumbs all over them when out for coffee and cake too :-))