my boyfriend and i have been having sex for about a week, for the past 3 days my perineum has been swollen and sore...ive looked and there are no sores, feels like a burn , like it did after i had my kids, it burns when i urinate, even moving in certain ways- ive never came positive for herpes , or any stds, and this has happened before its just been a long time. what could this be? what should i do