My first go on ICSI was successful and it was the most ridiculously stressful time at work.
I am the shop steward and had to accompany a handful of my colleagues to termination interviews that no one (except me), had any warning about and then I had to sit down with bad faith negotiators in management who would just try to make things personal and try to stare me out, rather than make proper arguments. This was all going on right through fertility treatment to 10th week of gestation.
Meanwhile, those who knew I was having IVF were all "remember to stay calm, don't stress, you don't want to hurt your chances, the baby feels what you feel" which I heard as "if you experience the emotions that are appropriate for this situation, you will kill your unborn child" which just made me cry most of the time.
The ET was very upsetting because of complications from a congenital pain condition that I have. I walked home from the clinic in floods of tears. I was completely wracked with guilt that feeling traumatised from what had just happened would ruin the transfer. I kept thinking about all the women in forums who lay down for half an hour after the transfer, with comedy videos and glasses of wine, while I was walking and sobbing on my own.
I'm due in a few weeks.
Unless we're talking war zone/famine level stress, don't give it a second's thought. In fact, I read somewhere some stress is supposed to be good for the growing embryo because it provides a more stimulating environment. Wish I could find that link, it was in a medical journal and everything!
Can't recommend Headspace meditations more highly. While I do not believe that moderate stress is harmful to the foetus, it sure does make the mother feel uncomfortable so it's nice to have a proper release.