The one that is decided within hours

One practical question comes up faster than any of the others and almost nobody warns a woman about it.

After a miscarriage, is the bleeding nifas, which suspends prayer, or is it istihada, which does not. The answer turns on the same gestational question of whether the child had discernible human form, and it therefore differs by case and by school.

This matters within hours rather than weeks, because she is lying there deciding whether to pray, on a day when getting it wrong in either direction will sit on her for months.

Ask, quickly, and ask a person rather than a search engine. One message to a scholar or to a knowledgeable woman at your masjid, with the gestation in it, gets a real answer the same day. If you cannot get an answer immediately, that delay is not a sin either.