Bleeding and postitive pregnancy testes

Patient: I took 3 pregnancy testes yesterday and they all was positve and then i started bleeding like regular period. i went in to see my doctor and there test was negative. i just dont understand why the testes i took was positive. i had been off my birth control for 3 weeks. my period wasnt suppose to start till next week, the first day of my last period was october, 16.

Doctor: