Leviticus 20:18

20:18 If a man has sexual intercourse with a menstruating woman and uncovers her nakedness, he has laid bare her fountain of blood and she has exposed the fountain of her blood, so both of them must be cut off from the midst of their people.

Leviticus 12:7

12:7 The priest is to present it before the Lord and make atonement on her behalf, and she will be clean from her flow of blood. This is the law of the one who bears a child, for the male or the female child.