Is this spotting, do I need to go to the doctor?!

I've had a very very small bit of gunky brownish red discharge over the last 3 days. I'm not pregnant, but I was wondering if there might be something wrong? My last period ended Feb. 3rd (it's now Feb 22), and I do have a history of irregular period. Do you think this irregularity is worth going to the doctor over? And I don't usually have spotting, it's only happened one other time since last May