determining day 1 of period

allie

hey ladies! So I'm having a hard time each month determining my day 1 of my cycle. AF due any day and after sex today I had red blood but not much, now for the next 2 days I will have no bleeding or just brown spotting...and then heavier red, dark blood for a couple days. do I count today as Day 1?! I need to take femera starting day 3 so this weird bleeding screws me up every month! HELP!