In terms of resources, I cannot praise The Myth of the Perfect Pregnancy: A History of Miscarriage in America by Lara Freidenfelds enough. It's a very comprehensive overview of the experiences of those who had miscarriages and those who had opinions about them from the colonial to modern era. I highly recommend it.

First to ectopic pregnancies. Prior to the modern era, in the overwhelming majority of cases where a fertilized embryo implanted somewhere other than the uterus, the person died. One paper estimated the mortality rate in 1880 was 72-90% (by 1990 it was down 0.14%) and that was during the early phases of modern medicine. Surgical solutions such as the removal of the fallopian tubes were developed in the late 19th century but they were rudimentary and often failed as symptoms of an ectopic pregnancy weren't obvious until it was often too late to save the pregnant person. Advances in safe abdominal surgeries increased the likelihood a person wouldn't die from the complications of the pregnancy itself, but there was always the risk of post-surgical complications. Or, in many cases, especially in 1940s and 50s, doctors performed abdominal surgery on a pregnant person thinking the cause of their symptoms was an ectopic pregnancy but discovered that wasn't the case. A useful resource on the topic is a 1992 article in the European Journal of Obstetrics & Genecology and Reproductive Biology by Samuel Lurie. (Edit: it's implied in my answer but I probably should have said it outright. One of the reasons the death rate dropped so dramatically in the case of ectopic pregnancies was timeliness. Prior to the modern era, people died because the pregnancy grew too large for the space where it had implanted, resulting in internal bleeding or infection. Even in the modern era, with medical advances such as sonograms and ultrasound, a timely response is essential for saving the life of the pregnant person.)

To miscarriage. A detail that is occasionally banded about is that the technical, medical term for a "miscarriage" is "spontaneous abortion." In response to a question about contraceptive teas, I offered some context about what such teas may have accomplished and it's worth stating explicitly, that when induced via chemical means (plant or medication), there is no biological difference with regards to the reproductive system (or to what a medical professional can detect) between a miscarriage and an abortion - the person's uterus expels its contents and lining. This detail helps us better understand how complicated pregnant people's feelings were - and are - regarding a pregnancy not going to term. The line between miscarriage and abortion hasn't always been as bright as we like to imagine in the modern era.

If a miscarriage is a bad or imperfect pregnancy, a theme Freidenfelds explores is what it means to have a good, perfect, or easy pregnancy. To state it explicitly, there's no such thing as every pregnancy was (and is) different. Meanwhile, how a miscarriage was dealt with depended on the pregnant person's class, religion, and location (and when in time we're talking about - the difference between 1850 and 1950 is not small) and the timing of their pregnancy at the time of the miscarriage. In addition to Freidenfelds, authors like Nora Doyle, in her book Maternal Bodies: Redefining Motherhood in Early America documented how a miscarriage could evoke relief or heartbreak, disappointment or sadness. Some women (then and now) had multiple miscarriages and began to fear every pregnancy, seeing each loss as a personal failing. (Sneezing too hard was cited as a cause for a miscarriage. Sneezing does not cause miscarriages.) At the same time, those who were eager to be pregnant expressed concerns about a lack of sickness or signs that they were pregnant. Beyond the emotional matters of losing a pregnancy, there could be physical complications when a miscarriage happened closer to a person's delivery date.

The most common complication was sepsis - or infection - due to an incomplete miscarriage. If tissue remain following the miscarriage, even a small amount, it was likely to lead to an infection. For someone with access to reliable, trustworthy gynecological care, in the form of a doctor of midwife, they might be treated with herbs or plants to encourage their uterus to contract and continue to expel matter. Even if all of the issue was expelled, a miscarriage could lead to hemorrhaging that could easily be fatal. There were other herbs and remedies that could stop the bleeding, but they often came with their own side effects.

Tl;dr: Ectopic pregnancy? You probably died. Miscarried? It's complicated.