Started Using Althea. Have Spotting. Transvaginal Ultrasound Suggested. Had Unprotected Intercourse. Pregnant?

Hi Dr, this is the first time that i will usng ALthea as recommended by my OB. I started with the first pack on the ist day of my menstruation and religiously taking it but today is my 12 day on the pill but still having spotting from light to color red. My OB suggested me to have a transvaginal ultrasound . Is this a normal reaction for taking Althea? This is the ist time I have experienced this. My fiance and I had unprotected intercourse on the 11th day of the pill, am i now safe from getting pregnant. Thank you for your response.