I answered a similar question a few days ago that you might find useful: How were ectopic pregnancies and miscarriages dealt with pre-Roe?

A few things to highlight: the detail that makes it possible for doctors to save a pregnant person's life in the case of an ectopic pregnancy is early detection and prompt treatment. Prior to common use of ultrasounds and sonograms, it was difficult to know the exact cause when someone was complaining of lower abdomen pain. Even if person providing medical care suspected the person was pregnant, determining the exact location of the extrauterine pregnancy was difficult. Without detection as a routine part of an early in a modern pregnancy check up, pregnant people typically don't become aware that the pregnancy is ectopic until the embryo has expanded the Fallopian tube to an uncomfortable degree and is about to rupture.

There were no common euphemism for it, as far as I'm aware, as it wasn't well-understood biologically speaking until the modern era. This is likely because of the lack of understanding around exactly what happened and that in many cases, the pregnant person may not have been aware they were pregnant. Assuming that missed period = pregnant is a fairly modern construct and before the modern era, the most common way someone confirmed they were pregnant was as a result of the "quickening" - or the first time, the pregnant person feels the fetus move. An untreated ectopic pregnant is fatal months before that point.

There are some mentions of ectopic pregnancies in the historical record but as far as I'm aware, most of the mentions are related to findings during an autopsy of someone who died as a result of the ectopic pregnancy or the embryo was discovered during the autopsy of someone died of other causes.