I'm usually very regular, it was supposed to be on the 8th of December.
Have you missed your period, if so when was it due? If you had missed your period when that poregnancy test was taken then most likely you arent pregnant. If you dont get your period in another week then I'd take a trip to see doc again. Take a pregnancy test at home to ease your mind.
Have a beta blood test done. It will be more accurate by showing the exact amount of hCG in your blood. This will tell you without doubt if you're pregnant or not. Cramping can be a sign that your period is starting, or it could be early pregnancy. It's impossible to say either way really.