Well I called and the nurse said it could be just be break through spotting from the Prometrium or it could be my period trying to start. I am supposed to stay on my medicine until I get "full flow". If that happens I am supposed to quit the medicine and we will know I'm not pregnant. If I don't get full flow, then I test on Tuesday and let them know. It's already getting heavier, so I guess we just wait - my absolute favorite thing to do in the whole entire world.