Is the yellowish or brownish discharge that appears after seeing dryness considered menstruation, especially during a girl's first menstruation, and when these discharges recur after purification and before complete dryness, bearing in mind that the questioner does not know the usual number of days of her menstrual period?

If a woman sees yellowish discharge after experiencing purity (ṭuhr) in the first menstruation, it is not considered menstruation. Yellowish or brownish discharge is not considered menstruation unless it occurs during the accustomed period or is connected to blood. A woman recognizes purity by one of two signs: dryness (when a cotton swab comes out clean after being inserted) or white discharge (al-qaṣṣah al-bayḍā’). So, if she sees blood followed by yellowish discharge connected to it, it is menstruation. But if she experiences purity and then sees yellowish discharge, it is not menstruation.