Unusual period

I just recently got my period a couple of days ago and instead of heavy flow of red blood, I have been having a medium flow of Brown and dark colored blood. Km not sure if I should be worried or not. I'm not completely sure. I didn't get my period last month but that's usually expected sometimes because I have irregular periods and I know I haven't been pregnant because I haven't been having sex. So I don't know if I should Be worried about this or not