Thanks for the query.
If your girlfriend had only you as a sexual partner, and you have never had intercourse, there is no chance of pregnancy. There are other causes like thyroid dysfunction, pituitary changes, obesity, stress, anemia and hormonal changes, etc which can delay a cycle.
Hope this helped.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.