I am 20 years old and had sexual intercourse with my girlfriend who is also 20. We used a condom, it wasn't supposed to be her ovulation period (we had sex 5 days after her last period ended), and there was no ejaculation (it was only our second time and she found it too painful, so it didn't last for even 3 minutes). She started spotting 5 days later. We took a home pregnancy test the same day and it was negative. Ultrasound the next day also said no pregnancy, and the doctor said it's a hormonal imbalance. She prescribed Diane 35. After the first dose, my girlfriend felt nauseous and vomited. Nausea persists after every meal. All this happened a week within we had sex. Could there be a chance?