2,078. Consecutive Days That Aren't Connected

Hilchos Issurei Biah 6:18

If the zavah immerses on the twelfth day after sunrise, she is prohibited to her husband until evening just like any minor zavah. If her husband violates the law and is intimate with her, neither of them is liable; even if she sees blood on the twelfth day after they were intimate, it is inconsequential. This is niddah blood and not connected to the blood of the day before.

Hilchos Issurei Biah 6:19

If the woman sees blood at the end of her seventh niddah day during twilight (which is questionable as to which day it belongs) and she then sees blood on the ninth and tenth days, then there is a doubt as to whether she is a zavah. This is because maybe the blood she first saw was on the eighth night and she saw blood on three consecutive days at the start of her zivah days. Similarly, if she saw blood on the ninth and tenth days of her zivah days and then saw blood again at the end of the eleventh day during twilight, there is a doubt as to whether she is a zavah; maybe the last blood she saw was on the eleventh day and she saw blood on three consecutive zivah days.