Suggest Treatment For Irregular Menstrual Bleeding

Hello I am 31 yrs old and I am experiencing a weird cycle this month. My period was to start on Sunday, 7/13 however I only experienced slight spotting late at night going into Monday. Monday I had a normal flow. Tuesday my flow got lighter. Then it completely stopped by Wednedsday. Then today it started again this afternoon and lasted for a few hrs and then stopped again. Can anyone help as to what may be the cause?