I'm 29 weeks pregnant right now, but at 6 weeks, I had a misdiagnosed miscarriage. I think probably a combo of implantation bleeding and a subchorionic hematoma that was later discovered. The ER docs definitively told me I lost my baby, though. So it was understandably traumatic and difficult, and in order to confirm, first that it was a miscarriage, and then that it wasn't, and then a usual dating ultrasound and to make sure an issue with the gestational sac measuring a bit small was resolving, I had to have an ultrasound at weeks 6, 7 and 8.
I am in midwifery care (in Canada, BC to be exact).
Anyway, I had a really really difficult time becoming excited about the pregnancy again because I was completely gutted by the miscarriage "diagnosis" and then having to get on board with being pregnant again after I had kind of come to terms with losing the pregnancy. I found that the time I felt the best about the pregnancy was at my 16 week appointment when I heard the baby's heartbeat for the first time with the doppler. I did a bit of research and decided to get a home doppler to mitigate the extreme level of worry and anxiety I was feeling, or to help me become more attached to the pregnancy. from weeks 16 to 24 or something, I would check in daily for a moment or so. I became really good at finding the heartbeat right away and eventually I would just click it on enough to hear a few beats and then turn it off. Once I started feeling the baby more (I have an anterior placenta, so this was kind of delayed), I stopped using it regularly.
Earlier on, my mother in law had guilt-tripped me over the "excessive" ultrasounds I had earlier on in the pregnancy (I've had five over all, three in early pregnancy and two anatomy scans because my son was too low to properly examine in the first one -- I declined genetic testing so I felt the anatomy scan was a good idea -- if everything continues to go as well as it is now I probably won't need another one for the entire pregnancy), so I decided to do some research. I have found that in a lot of natural/attachment parenting literature that most of the doppler research is for the doppler ultrasounds, and not handheld dopplers. I have found that it seems like people often conflate the two and it amounts to (what I feel is) misinformation.
I would be slightly curious to read the information you're citing -- because as far as I know, based on everything I've read (which is quite a bit, but I'm obviously not an expert), a handheld doppler is considerably less powerful than an ultrasound, and the most troubling findings have been with the doppler ultrasound, which as far as I know is quite rarely used and only for diagnostics when serious problems are suspected. When I enquired with my midwife, she seemed to support the idea that a lot of the negative findings were with pulsed-wave doppler ultrasounds, NOT the handheld devices.