My girlfriend's period is 4 days late and she and I had sex and used condoms as birth control. I took her to see a gynecologist. The doctor examined her, took a sample of fluid for a fresh smear, gram stain, and ultrasound. The test results showed that my girlfriend had a lot of bacteria and gram-positive cocci. The ultrasound showed a benign ovarian cyst measuring 18*21mm (the doctor did not mention pregnancy). The doctor told me to clean myself regularly. Doctor, can you tell me if my period is 4 days late, is it a sign of pregnancy?