Do i count the brownish spotting at the end of my menstrual cycle as day 5 or i count the last day that i had with regular blood flow as my last day?

Days of period: If it looks like old blood (all brown), then that means the actual bleeding stopped a day or so prior to that. If there's any bright blood, then you're still on your period it's not a super exact science, so being off by a day or two doesn't make a difference for most things. For pregnancy, we care more about what day your last period started.