Weird period?

Here's a few things you should know: I'm not currently on any kind of birth control, but I was on the depo shot well over a year ago. I remember it took about 3 months for me to start bleeding again and everything since then has been fairly regular which is heavy bleeding lasting about 3-4 days. My last period wasn't so normal.

My last period was well over 20 days late. When I started bleeding it was light and lasted only about 2 days. My next period isn't due for another 10 days. I started spotting Thursday night. Didn't notice it until I went to use the restroom when I wiped. At first it was a light red color, then pink, and now it's just brown. It hasn't been enough to wear a tampon and hasn't leaked onto my underwear. Normally during my period I wear a tampon and pad because it gets really heavy. Should I be worried about this?