I'm 58 - and when I was pregnant (during the 80's) no one told anyone they were pregnant before 12 weeks. It was considered unlucky.
I had 3 miscarriages between 1985 (when I had ds) and 1989(when I had DD) and I never had anyone to talk to about it - first one I had (at 8wks) my (male) GP said to me 'oh it's no more than a period really, you girls always get yourselves in a state about these things' (I hadn;t'got myself in a state', he was just being patronising)
2nd one was an ectopic pregnancy - and I had far more care surrounding that becase it was a physical operation I think and I was very ill - easier for people to deal with than someting emotional probably.
The third one - I was 20 wks - and they found no heart beat at my scan. sent me home for 2 weeks then I had to go back fro another scan and was told the baby was dead. On that occasion a nurse said to me 'it wasn't a real baby because it obviously wouldn't have lived anyway, so nothing to get upset about'.
I think there was a much more 'brush it under the carpet' attitude. But I might just have been unlucky.
I don't know how much aftercare women get now after a miscarriage, because obviously I haven't been pregnant fro many years, I hope it is better than I got. When I did eventually become pregnant with my DD I had a very kind Australian consultant and he was far more willing to talk about my previous miscarriages and the fears I had surrounding my pregnancy because of my prior experience.
I imagine miscarriage was more common in years gone by, simply because pregnancy was more common - people weren;t able to plan thier families in the same way they are now, and so got pregnant more often - that's going to mean higher incidence of miscarriage.,
So maybe it was considered in a more matter of fact way, or maybe as you say people couldn;t test early and so didn't even know they were pregnant. (I bled for the first three months of my pregnancy with DD only testing told me I was pregnant)