Possibly. Purchase and perform a home pregnancy test. They usually become positive when you are about a week late. If it's negative, repeat in one week and call your doctor.
No, not at that time. A girl cannot get her normal regular period and be pregnant at the same time. However, she can get pregnant a week or two after her normal period. If she has some spotting or light bleeding that doesn't look like her normal regular period, she can check a urine pregnancy test about 3 weeks after sex (when conception might have happened) to see if she is pregnant.