pelvic pain the morning of my new cycle

Today is supposed to be the first day of my new cycle but it hasn't started yet. I have paraguard so I don't think I'm pregnant but I kept waking up in the middle of the night with this pain all over the outside of my vag, like my lips and everything. It just felt like someone had been punching it or something. Any idea what that could be? Has anyone else experienced this pain?