For the past 2 months I'd say, I've been having muscles spasms in my uterus or that is where it feels. My first thought was a baby kicking because its almost exactly how it felt at week 20 when I felt my daughter kicking..the fluttering feeling. I seriously doubt I'm pregnant. I've been on birth control since last February and I take it perfectly. I've never missed a period either. I'm wondering if this is a cause for concern?