What is this??

Sometimes at the beginning of my period, I would spot but the spotting is a light brown. It happened a few times but until now, it hasn't happened in a couple months. Throughout my period this month, July 8th till today, I've had regular period and this brown stuff. A close friend of mine said that it happened to her but it's only dried blood. That seemed reasonable but today it seems like I'm not bleeding, just the brown stuff. Should I be worried or is this normal?