Thank you, all three of you!
Panicnot and Suzy: I think you're right that it's easy to get overwhelmed by internet coverage of the risks of being an older mum, even though if I'm even slightly rational for just a moment (struggling with that during these last weeks), I know that there's still a very much higher chance that my pregnancy will come to term and I'll have a healthy baby than not. It's always good to hear from mums of a similar age for whom it's all going well. One of my friends has just had a second baby at 39 after a fairly straightforward pregnancy, so I do know it's possible! But I'm just a mess right now!
Dldj: yes, like you, I've not had much in the way of symptoms, apart from the dragging tiredness, and while I should count myself lucky, I think I'd find it a bit of nausea reassuring!
Suzy: thanks for encouraging me to stop and think about where all the worries are coming from. I think the causes of my worry might be similar, i.e. it's possibly because I feel so lucky already (1) to have met my wonderful partner, and (2) to have had my first gorgeous baby (daughter, now 16 months) at age 38, and (3) to have got pregnant actually very quickly this second time when I was fearing it just wouldn't happen, that a bit of me thinks that surely the luck has to run out some time soon, ridiculous though that sounds. And yes, I do so want this baby, so I think the pessimism and holding back is also about not letting myself get excited because I'm really worried I won't cope well if something goes wrong.
Never mind the physical exhaustion of being pregnant - it's emotionally exhausting too, isn't it! And I'm sure my husband thinks I've gone just slightly mad.
I think I'll hold off booking a scan until I've seen the midwife at 8 weeks (a week on Friday), and perhaps just getting to that stage will make me feel a bit more positive. And if I go for the scan, they should definitely be able to see a heartbeat at that stage, if all is well.
Very good luck to the three of you, and perhaps meet you again here - perhaps, if all goes well, next time I'll be worrying (of course!) about telling my employers that I'll be off on maternity leave again within a year of returning to work... really not looking forward to that discussion.
I hope your pregnancies continue to go well. All the best, CC