Hi Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern.. Most common cause of Intermittent vaginal bleeding or light spotting after having sex is bleeding from cervix ( the lower part of uterus). Cervix has high blood supply & Even when cervix is healthy, vigorous or rough sex as you mentioned can cause some bleeding. This mostly occurs when you have vaginal dryness or less vaginal lubrication. Intercourse can also be painful in this case. You should use lubricant during sex. Vaginal moisturizers give long term relief from vaginal dryness However if bleeding persists or reoccurs, it could be because of some abnormality in cervix. In case of cervix abnormality, even gentle sex in presence of enough vaginal lubrication could cause bleeding. In case of reoccuring bleeding you are advised to consult a gynaecologist & a pap smear test should be done to rule-out cervix problem. Refer to a gynaecologist. Hope this information helps