My last period started on August 6th, 2016 on August 21st, 2016 early in the afternoon I noticed brown light bleeding in my panties it lasted a few hours of spotting and then stopped with light cramping. A few hours later I went to the bathroom nothing was on my liner or in my pee but when I wiped it was a lot of red blood. Overnight it was fairly normal flow of my typical period. My typical cycle is between 28-35days I track it using m. Cycle app. I am sexually active. My question: is it concerning that my menstrualcycle is only 17 days long this month?