Is it permissible to pray and fast during the days when menstrual bleeding is intermittent (consisting of spotting) for three days, one week before the original due date of the period?

The mentioned spotting is considered menstruation under two conditions: that its discharge occurs fifteen days or more after the last period of purity, and that its discharge continues for a day and a night or more. If these conditions are met, then neither prayer nor fasting is permissible or valid.