For me it's not really a concern, the whole jinxing thing. Sure, something may go wrong in this pregnancy. But then we try again, and again. And when eventually we give up we go to surrogacy. If that doesn't work we adopt. Whatever happens, we will get our take home baby. Whatever the costs. So if I buy a few things now, it's really not going to affect us long term.
I respect that other don't or can't think that way, and that's fine. Everyone needs to do what's right for them. But for me to think positively and assume all will be well, that's my rock 😄