What Causes Light Spotting And Discharge After A Period?

Hi, I am an 18 year old female. I recently saw my gyn for a check up and she said everything looked fine. I have been taking oral contraceptives for over a year and have had very regular periods with medium to heavy flow, about 5 days long. My most recent period started a little late and ended a little early and was a little lighter than usual. Since then I have had some light spotting and dark brown discharge. I have not missed any pills in at least several months, maybe longer. Should I see my doctor again or wait until my next period to see if I'm back on schedule?