2 day period

SHAUNA
I had a normal 5 day period 3-21 to 3-25....april 16th i had a short period ending on april 18th. According to glow calendar AF due may 8th.... thats only a 23day cycle...i have a normal 28 day cycle for the most part. I start cd 25 to 28. If i go 28 days that be may 13th. . This short period has my calendar messed up. What do i do