Help me

Patient: I was with my girlfriend this may and its been three months since we had sexual intercourse she has had irregular periods all her life and her stomach hurts when she lay on it and her back hurts here and there is she possibly pregnant? and to note we didnt try to have intercourse because we young and there was precum but im sure i didnt do it in her at all please tell me is there a possiblity she is pregnant or there is something else that could be wrong with her