text: vaginal bleeding? just a quick question. this last couple of months i've started bleeding after sex and it's been quite painfull. we've been living together for 2 years and i've never had a problem before. any ideas?? sometimes the thickness of our uterus changes and gets thick. it'll cause spotting during activities such as sex, running upstairs, hitting a bump in the road. best to have it checked out to make sure.