Kindly refer to the following link(s):


https://www.assimalhakeem.net/i-get-spotting-before-a-period-begins-sometimes-it-happens-a-few-days-before-the-period-and-sometimes-a-few-hours-before-the-period-can-i-continue-fasting-and-praying-in-this-state/

You have to continue fasting and praying until the blood flow is established.


Spotting before and after periods or menses


Seeing blood or spotting after the menses / period ends 


It is not considered to be menses until the flow of the blood has been established






And Allah Knows Best