I had written a response, and just as I was about to post it, my Internet connection died and lost the grrrr.
So here is take two. Apologies if it doesn't make sense.
Look after you and your baby.
Speak to HR and find out company policy.
Look after you and your baby.
Speak to your line manager about your concerns and discuss what you can do.
Look after you and your baby. You would feel far more guilty if you put others first for fear of upsetting them, but don't be bolshy about it, as much as it is tempting to snap!
Look after you and your baby.
When you get home from work, turn it off and relax. Do some stuff for you, and spend some quality time with the other half
and...
...
Look after you and your baby.
I am finding work stressful too, although not too bad, but taking my advice and have just made it real to them by handing in my MATB1 form :)
The baby goes quiet when I am too stressy, and I don't like that, but it is a good indicator for me :) I am 24 weeks, so it could just be that the baby isn't big enough to feel it all the time quite yet, but the kicking makes me smile and remember what is important.