New to Glow

I am relatively new to Glow.  My husband and I have been ttc for about 9 months..with serious ovulation tracking for about the last 3.  I have never used this type of app before so I figured "what the hell".  I want to ensure I am correctly inputting my period information so I can receive the most benefits from this app.  My period has always been fairly regular but I usually spot for 3-4 days prior to fully starting my period, bleed heavily for about 3 days, and spot for about 2 days at the end.  My question is this: Do I input the initial 3-4 days of spotting as the start of my period or do I wait until heavy flow to mark it as my period start date?  Any assistance would be greatly appreciated!!