Hello,
Aside from pregnancy, a delay in the menstrual period could be due to physical or emotional stress, depression, malnutrition, sudden weight loss or gain, certain drugs, medical conditions (such as polycystic ovarian syndrome, thyroid or adrenal gland problems), breastfeeding, or others. If there is even a slight possibility of you being pregnant, you may do a home pregnancy test (HPT) one week after your missed period. For proper evaluation and management, I suggest she consult a doctor (OB gynecologist). Blood tests, pregnancy test (serum bHCG - more sensitive than HPT), vaginal smear, ultrasound may be done. Treatment will depend on the cause.
I hope it helps. Take care and regards.
have you had unprotected sex or are you on a contraception? have you taken a pregnancy test. the answer to your question is maybe yes