Can i pray when spotting ?
Salam, I want to know if I can do my namaz on the onset of starting my period when I’m only spotting. My periods are usually really light & lasts 5-6 days. Thank you. Answer: ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﯿﻢ In the name of Allah, the Most Gracious, the Most Merciful
For example, if your normal menstrual cycle (habit) is 6 days, then any blood seen during this time will be considered the blood of menstruation irrespective of the amount of blood (even spotting). Therefore, it will be prohibited to pray during this time, i.e. during the days of your normal menstrual cycle. 
Only Allah knows best
Written by Maulana Mohammad Ahsan Osmani Checked and approved by Mufti Mohammed Tosir Miah Darul Ifta Birmingham
 Islamic Academy of Coventry- An Introduction to Female Hygiene from An Islamic Perspective (3rd Edition): p. 8-10; Behishti Zewar: p. 92-94 (Darul-Ishaat)