long than normal period?

usually my period is 5-6 days with the last two little to no flow. the past couple months it's been about 3-5 days, my flow isn't usually on time either. and my tale sign that I have ended is I get a splotch of brown goop in my pad.

this month I am on 10 days, I thought it ended on the 5th, I had no flow at all but I didn't get the brown goop. I shrugged it off because my flow is irregular. the next day how ever I spotted and had mild cramps. then later that night I got the brown splotch. and every day since it has followed that pattern.

any one know what's up and if I should be concerned?