Is the prayer of a woman valid after the discharge of a brownish fluid following lower abdominal pain after the end of her menstrual period, and what is the nature of the discharged fluid?

What the questioner saw is not menstruation (hayd); because a brownish discharge (kudra) after seeing purity (tuhr) is not considered hayd. And even if she were to see blood, it would likewise not be hayd, because it occurred at a time not suitable for menstruation. The interval between its two ends exceeded fifteen days (the maximum duration of hayd), and it was not interspersed with a period of 13 days (the minimum duration of purity). Therefore, her purification and prayers are valid. She may consult doctors regarding what she experiences.