Hello and welcome to HCM,
There is a history of urinary tract infection
UTI is associated with increased frequency of micturition, burning micturition, lower back ache, nausea
You need to get urine examination and urine culture for isolation of the organism causing the infection.
The other problem that you are facing is that of brown colored discharge few days before actual menstruation
Sometimes, ovulation is associated with slight lower abdominal pain
and light spotting. This occurs 14 days prior to menstrual cycle.
There is nothing to worry as it is a normal physiological phenomenon.
However, if the bleeding is severe, you need to consult your gynecologist for clinical evaluation and relevant investigations.
Thanks and take care
Dr Shailja P Wahal