Whenever you want and whenever you can be bothered to be honest.
I think it's that you'll feel the urge to. Hasn't come to me yet and I'm also 35+5.
I never did with my first, I just wanted to veg out tbh 🙈
It never did kick in for me with my first and I was on maternity 3 months early due to my job at the time
With baby 1 it was pretty late. I remember cleaning the tops of the kitchen cupboards the week she was born and being told off. It was sudden and manic 😂 I’m 35 weeks now and starting to fuss over laundry but no mad nesting yet.