When should I start taking my pill again??

I recently posted about my doctor advising to start only having 4 pill free days rather than 7 before starting my next lot of pills, however it always takes me about 3 days to actually start the withdrawal bleeding after I finish my pack (unfortunately I didn’t think this it the time so didn’t ask doctor). Does anyone have a similar experience? how long do you leave between packs of pills and how long does your bleeding take to come and how long does it last?