Is it possible that I have had a miscarriage?

Yesterday I went to the doctor at 10.2 weeks and the nurse AND doctor both tried finding the heartbeat with the doppler. They were unable to find it and now I am very worried. I haven't had any discharge or bleeding and my morning sickness still continues every day. The only difference I've really noticed is that my don't hurt as much. Is is possible that I've miscarried? I'm going crazy and I need something to ease my mind. :( Help?