what's going on with my period!?

This is the most strange period I've ever had. Usually I get my periods and after the first day it kicks in and it's a crime scene then it slows down about a day or two before it ends. But this one has been a completely different story, to begin with I had brown spotting the first day and it was like blood but nothing but brown and light pink and usually that doesn't happen till the end of my period. Then my period started and it's been a light flow to the point where sometimes I forget I'm even on my period but everyday so far with this period I've had constant blood clots.. has this happened to anyone before? Can I get any advice on what this could be or is it normal??