One who has forgotten her habit.
Useful information: If blood is discharged from a nasiya (i.e. a woman who has forgotten her habit) with signs of menses and the period involved is not less than 3 days or more than 10 days she should consider it to be menses. In case, however, blood W discharged for more than 7 days she should consider the period for which her habit is likely to remain stable to be menses and consider the remaining period to be istihaza. However, if her habit is likely to remain stable for more than 7 days and up to 10 days she should observe precaution after the 7th day.