Regulation of period question

Mary • Hi! I`m Mary. I have a BA in Psychology. Been dealing with PCOS for 22 years. I work at Sander’s Candy and Ice Cream Shop and trying to get my head around this COVID craziness!
Hi everyone, 
I use birth control to clear up my complextion and regulate my period. Does anyone know how long it takes for the regulation effects to kick in? 
Thanks!