Should a woman pray if she experiences light red bleeding without pain or odor at the time of her period, and then it slightly increases on the third day with back pain less than usual, knowing that this condition has not happened to her before?

The basic principle concerning blood seen by a woman is that it is menstrual blood unless proven to be istihada (non-menstrual vaginal bleeding). Accordingly, if blood appears at a time when it is possible for it to be menstruation, she should abstain from fasting, prayer, and all other things that a menstruating woman abstains from, without regard to its characteristics, because that is specific to istihada. The blood is considered menstrual if it appears after the minimum period of purity has passed (13 days according to the Hanbalis and 15 days according to the majority of scholars). This ruling continues to apply if its duration, including the period of purity, does not exceed 15 days.