What Causes Pain And Tenderness In The Lower Abdomen?

Hi. I m a female, 28 years old. I felt absolutely fine yesterday & then last night, all of a sudden, I had an onset of intense pain in my lower abdomen/pelvic area (like, where my uterus is). It almost felt like tons of little explosions. I am not a wimp about pain and I immediately had to lay down. I took ibuprofen & the intense pain subsided after about an hour or two, I would say. However, now, I am incredibly sore. It hurts to push on the area. It is all very tender. I can feel it when I breathe. It hurts when I sneeze/cough/move around too much. I just wasn t sure if this was as simple as something like a muscle strain, or something serious. Thanks. - Desirae