You have not mentioned when you attained the menopause - that is, complete stoppage of menstruation for 1 year. However, this bleeding is abnormal at this age. It could be due to some benign lesion or due to cancer in the genital tract or due to injury (like during intercourse). You must be examined by a gynaecologist immediately and he/she can then chalk out the further tests that need to be done - a Pap smear and an ultrasound of the pelvis are a must.