need some advice or input please.

past 4 days I've felt a lot of pressure in my uterus with cramping, started getting headaches which I never get. I was finishing work two days ago felt like someone piled bricks on me felt like my body was very heavey. Each day I find I become more and more tired. Today was really weird for me, every time I ate I felt nauseous. further in the afternoon the nausea hit me harder. I've never had these things happen before. anyone else ever have this happen?