Period

Monique

How do you count your sickle days. Do you count 28 day from the day youbstart your period or the day you end your period? I have 3 <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period calendar</a> apps and the one says i am 2 days late and this one says i am in 4 day till my period?