Brownish Colored Discharge

So I added this app because I NEVER know when my cycle will start and I figure this will help me start keeping track. Sometimes I have spotting before my cycle starts, but not often.
That being said, I am a little concerned because today I went to the bathroom and I saw what I thought was blood. Only this time was different. It was much darker almost brownish red and there was mucous. There was no smell and I am not experiencing any pain, discomfort or excessive itching down there. I'm not sure if I'm spotting or if this is something else altogether. Does anyone have any advice about this?? Should I be worried?