Pain in pelvic bone and less movement

Si
Ok so two days ago the righ side of my pelvic bone was hurting the entire day. It sort of felt like a period cramp there. It would hurt when I walk but when I was laying down the pain would go away. The next morning the pain was gone which was yesterday. But all day yesterday I barely felt him move or kick. Has anyone experienced this before? Or think it's serious enough to go get it checked out?