p.s. - I'm on the Pill -- have been on the same one for many years, if that helps any.
While i was in college (the first time, lol) i had that problem, was not sexually active, was on the pill (to regulate periods) and was spotting. The gyno put me on a stronger pill (made me nauseated for a while) but it worked.
Hope this helps.
I had spotting like that while I was on the depo shot (birth control) It has stopped since then.