Could this be an std if discharge at other than usual time of month?

Yes.: It depends on the extent of infection, but infections like mucopurulent cervicitis (mpc) can have an abnormal vaginal discharge and bleeding in at least some cases. It can often be after sexual intercourse. Chlamydia trachomatis and neisseria gonorrheae are causes of mpc. And they can also cause long term problems like pelvic inflammatory disease (pid) which also might produce a discharge.