Hello, You had unprotected sex with your partner, she is now almost a week late, has not got periods. If your partner was not on any contraceptive device neither took any emergency contraceptive pill within 72 hours of unprotected intercourse then she can be pregnant. She is suggested to get pregnancy test done with the first morning mid stream urine. If positive, she will be managed accordingly. In case the test is negative and she still fails to get menses, she should wait for a couple of days and repeat pregnancy test. She should get clinically examined by an OBGYN, get per vaginal examination done to detect bulky uterus. The OBGYN may order for USG (Uterus with fallopian tube) to detect ectopic pregnancy. If pregnant to know the gestational age and well as the well being of the fetus. Other causes of delayed periods when not pregnant are anemia, poor general health condition, PCOS, hormonal problems, etc. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician