Really Irregular!! Help!

Okay I know I'm irregular but I think this is just ridiculous! So I had my period March 2nd - March 8th. On the March 17th I came home late from work and I had cramps and I'm thinking in my head oh no way I started my period! I go to the bathroom and I started!!! But I feel like it's not a regular period like red blood it's like reddish brown and it doesn't fill up a pad. It's the 19th and I'm still on this so called "period." Should I go to the doctor or what? My cramps are getting worse but they are mangeable. What do you think?