Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.

 

Assuming you had your regular monthly periods before this condition occurred, you ought to count the days of your previous pattern of menses as due to menses as long as you see brownish blood.

Any blood continuing after the regular pattern shall be reckoned as due to a chronic condition is known as Istihadah. In this case, you need to perform ghusl at the end of your estimated period and resume prayer and fasting as usual with one exception: you should wash your private part and perform ghusl close to your prayer.

Almighty Allah knows best.