Pain after D&C

I had a D&C on Tuesday and I've had really bad cramping and I bled Tuesday and Wednesday and then it stopped. Yesterday was my first day back at work and I worked a 15 hour shift. I started cramping and my stomach got hard and swollen (I still have my 8 week bump) I started bleeding again, but it looks like implantation blood. And about 1 this morning I jumped up out of my sleep and throwing up. I haven't had sex since last Thursday and it was not protected due to me already being pregnant. Is there something gone wrong here? Could I be pregnant or is my body just tired?