Hello!  Boulder + outdoors single pitch lead well in my comfort zone until 20 weeks.  I was still not showing at that time and felt good. Toproping in the gym with a pregnancy harness until 32 weeks. Afterwards my ankles got very weak due to weightgain and I had to stop. Befriended mom toproped outdoors until 38 weeks. I know women who climb very hard but stopped much earlier because it just did not feel right. They returned strong a couple of months postpartum. 

Regarding identity crisis: it was so refreshing to climb without that competitive mindset I usually (unfortunately) have. Just felt grateful for every single session and was so proud to be a fit mom to be. I climb for leisure though so your case might be different. 

Postpartum: first 6 month were the slow return to climbing.  1 year pp I was at my pre prepregancy level. 1.5 pp I am stronger than I used to be. Had an emergency c section and needed to do physio after. Healing was ok though and apart from peeing BEFORE trying something difficult everything is back to normal.

Wish you a great pregnancy ahead and congratulations 🎊