Hello and welcome,

A few years back before kids I had the same thing except mine was extremely heavy bleeding I went to the doctors and had a papsmere which came back abnormal so I had a colposcopy which turned up normal and I was told that some times there is old blood that doesn't come down and just sits there until something like penetration causes it to losen and come out. I have had a few friends that have had the same thing happen and there was nothing wrong. But I'd go see a doctor just to check