Genesis 31:35

31:35 Rachel said to her father, “Don’t be angry, my lord. I cannot stand up in your presence because I am having my period.” So he searched thoroughly, but did not find the idols.

Leviticus 15:19

Female Bodily Discharges

15:19 “‘When a woman has a discharge and her discharge is blood from her body, she is to be in her menstruation seven days, and anyone who touches her will be unclean until evening.