Tmi- desperate please help

Okay so I had four positive hpts, went for a blood test and it was negative. My friend had three negative blood tests and negative urine tests but she was pregnant and all day I've been reading countless accounts of this happening to people. The doctor told me that unless I start my period then I should treat myself as I'm pregnant because she's convinced that I am. I have every symptom in the book that go beyond any PMS symptoms I've ever had. I'm a week late. Well today I went to the bathroom and when I wiped I had some discolored discharge. (Pic below) just a tiny amount and it doesn't at all feel like my period is coming. My period generally comes with a vengeance and it's heavy right from the start. My cycle is also very regular. What's going on? Any insight?