Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
Abnormal
vaginal discharge post intercourse could be left over bleeding from your last period. Such a discharge is normal and not a point of concern. However, if it persists for a week or more, it needs to be investigated.
Uterine bleeding even after menses may be indicative of uterine polyps
Vaginal discharge after sex may be bleeding from cervix( the lower part of uterus). Cervix has high blood supply & Even when cervix is healthy, vigorous sex can cause some bleeding. This mostly occurs when you have
vaginal dryness or less
vaginal lubrication. In this case bleeding is somewhat lighter in colour (pinkish red)than your period.
Bleeding from cervix can be because of some abnormality in cervix, therefore must be investigated properly. In case of cervix abnormality, even gentle sex in presence of enough vaginal lubrication could cause bleeding. In that case you may be advised a
pap smear to rule-out a cervix problem.
Refer to a gynaecologist
Hope this information helps