What Causes Menstrual Cycle Problems?

I'm 27 years and have menstrual problems I've done checks for tyroid and fibroids and cyst did not show anything on scan my menses scanty n bleeding every day for the last four years with no full flow of period when I try certain herbs it helps with flow but now recentley I visited a homeopath who recomeneded pulslitta 200 drops in your opinion what can be the cause of it I like to add also this bleeding was triggerd by taking a birth control pill to avoid my period due to a holiday which I only took the white pil n not the red I also had this condition ten years ago n lasted 8mnths but normalised after a full period. Since the medication I've seen abit of a increase n nnow its stiky n darker what is this are these menstrual cycles normal