I'm currently in my 27th week. At night it started feeling like someth…

I'm currently in my 27th week. At night it started feeling like something was pulling at my belly as if during my period. I took some No-Shpu and it seemed to get a little better. In the morning it started again and now my lower back is hurting. The frequency is unclear. I took a shower and it seemed to calm down, but then it started again. The pain isn't getting worse. Has anyone experienced this?