by these changes. don't use it if you've had unusual vaginal bleeding, breast or uterine cancer, blood clots, liver problems, stroke or heart attack, are allergic to any of its ingredients or think you're pregnant. side effects may include headache, pelvic pain, breast pain, vaginal bleeding and vaginitis. estrogens may increase your chances of getting cancer of the uterus, strokes, blood clots, or dementia, so use it for the shortest time based on goals and risks. estrogens should not be used to prevent heart disease, heart attack, stroke or dementia. ask your doctor about premarin vaginal cream.