Am I pregnant? Can I wait 3 weeks to go to the doctor?

I am 3 days late, I dont have insurance coverage until january 1st. I have cramp like twinges every so often in my belly, i was thinking that was just prementral cramps but still nothing i am usually always on time, like 2 weeks ago my husband thought one of my areolas were darker than the other, major headaches and nausea, no throwing up though. I sleep alot, and now, moodiness...usually my period would be over by 10 am tomorrow! 12 hrs from now!!! Please help quick