First day of your last period
Average length of your menstrual cycles Between 22 and 45 (28 days normal) 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
Duration of menstruation Between 1 and 10 (7 days normal) 1 2 3 4 5 6 7 8 9 10