The menstruating woman may cut her nails and comb her hair. It is also permissible for her to do Ghusl whilst menstruating in the case of major ritual impurity if she has an erotic dream, or if her husband is intimate with her without having intercourse and she reaches climax.

Unintentional miscalculation of menses is not a sin. If a woman thinks that she has become pure and starts praying and fasting, then she realises that she is still menstruating, then she has to stop praying and fasting until she becomes pure, and she should make up the obligatory fasts that she observed during that time.