Hello, Me and my fiance had intercourse on 5th day after her periods w/o protection. After that she took an i-pill. 1 week later we used protection and no contraceptive. Her expected date for next period is 29th of this month but it is 21st and she experienced slight back pain with little blood in the morning. By evening the color of blood got darker. Blood flow is not continuous. We suspect it to be pre menstural bleeding but is it possible that it can be implantation bleeding or any other effect due to the contraceptive or any kind of infection ( we both dont have any std). Please help. And when should b take the urine test? And what measures to take next? Kindly suggest.