Alright. Here's what going on, I'm hoping to get some opinions before I go back to the doctors. I am just about three weeks late. I have always had very regular 28 day cycles. I've NEVER missed a period before. Aside from the missed period, I started displaying other symptoms of being pregnant, but I have taken 4 pregnancy tests, and had a blood test taken, all of which were negative. My confusion lies in that I'm still displaying symptoms of pregnancy (ie sore breasts and back, incredibly tired, mood swings, ect.) I realize all the evidence is pointing to not pregnant, but I was wondering if this has happened to anyone else, and what ended up causing it. I'm planning on waiting another week to see what happens, and if nothing changes, I'm going back to the doctor.