Niddah 10:3-4

Niddah 10:3

If a zav or a zavah checked themselves on the first day and found themselves clean, then on the seventh day they found themselves clean but they didn’t check on the days in between, Rabbi Eliezer says they are presumed to be clean, while Rabbi Yehoshua says they only have the first and the seventh days (making two clean days, so they must count five more). Rabbi Akiva says they only have the seventh day (because an unclean exam in the interim would invalidate the first day).

Niddah 10:4

A zav, a zavah, a niddah, a woman who gave birth or a metzora who died conveys ritual impurity by carrying until the flesh has decayed. A non-Jew who died does not convey ritual impurity by carrying. Beis Shammai say that all women who die have the status of a niddah; Beis Hillel say only those who died as a niddah.