I started my period 6 days after i ended. what does that mean?

Vaginal bldg: At age 37, not all bleeding is a "period", but may be coming from overstimulated uterine lining, from cycles which do not involve ovulation: your ovaries require more stimulation to mature an egg for ovulation. This produces more estrogen, and that makes the lining of the uterus much thicker, which can cause bleeding at any time. See your gyn for treatment/diagnosis.