Why Is The Color Of Blood Orange During Periods?

I am 28 years old and have had regular menstrual cycles with the exception of bleeding heavily and cramping more than usual the past several months (almost like labor pains at times). Last month I noticed during my cycle that the blood was an orange color. I though maybe it's the lighting or something and didn't give it second thought. Now this month I started 2 days early have orange blood again and VERY heavy cramping. Blood flow is moderate to heavy. What could this be? Do I need to be concerned?