Hi. This is so embarrassing but for a few months now ,once a month or so I have sharp pains in my vagina and anus. It feels almost throbbing .. Like when u sitt on a hard surface to long and your but bones begin to ache. Last week me and my boyfriend decided to try anal sex, it didn t hurt much while we had sex and not at all after. About 3 days after we had anal sex I began to experience these sharp pains again except 10 times worse. Its excruciating and has been so bad its keeping me awake at night it feels like the bones are throbbing down there. Any suggestions what it could be ?