2,082. Days of Comfort, Days of Pain

Hilchos Issurei Biah 7:3

If a pregnant woman sees blood for one day without pain, then for two days with difficulty, and then she delivers, or for two days without pain and then one day with difficulty, after which she delivers, or for one day with difficulty, for one day without pain, and for one day with difficulty, after which she delivers – in all of these cases, the laws of a woman who gives birth as a zavah do not apply. However, if she sees blood for one day with difficulty and then for two days without pain, after which she delivers, or for two days with difficulty and one day without pain, after which she delivers, or for one day without pain, one day with difficulty, and one day without pain, after which she delivers, then the laws of a woman who gives birth as a zavah do apply. The general rule is that when there are pangs adjacent to delivery, the laws of a woman who gives birth as a zavah do not apply; when there’s comfort adjacent to delivery, the laws of a woman who gives birth as a zavah do apply.

Hilchos Issurei Biah 7:4

If the third day of seeing blood is the day on which she delivers, then even if the whole day is one of comfort, the laws of a woman who gives birth as a zavah do not apply. This is because the day she delivers is one of difficulty. If she sees blood for two days and miscarries on the third day but she didn’t identify what she miscarried (i.e., whether or not she expelled a fetus), then her status is in doubt and there’s a question as to whether or not the laws of a woman who gives birth as a zavah apply.