If you know that you don't have a low lying placenta I would say it's part of your mucous plug. As Trillian said very often a show first presents like you describe.

Your very very wonderful body is letting you know that it is preparing for labour day. It's a good sign!

Keep an eye on it - I certainly had a show just like you describe with some fresh blood mixed in. About 5 days later I had my baby girl!

Good luck my love - if it continues with a large amount of fresh blood - pop up to the birth unit for an asessment.