My periods are usually 6 days. the las couple cycles i had my period for three days. two days it stops i'll have sex after sex there is blood. then next day it's a brown discharge a little pink for two days why has this been happening? i was also on depo

See gynecologist: If you are currently on depotprovera, then in all likelihood what you think are 3 day menstrual cycles are in all reality breakthrough bleedings and probably not exactly 4 weeks apart. The bleeding after sex could come from an ectropion on your cervix. You will need to see a gynecologist, who would need to do a speculum exam and then be able to tell you whether or not this is the case.