I had unprotected sex with my girlfriend yesterday and today

Patient: I had unprotected sex with my girlfriend yesterday and today she had pink spotting that I am worried could be a sign of ovulation. According to my girlfriend she has not missed a day of bc this month and she was on day 11 of her cycle. However she did tell me she had been inconsistent in the time she took her pills each day varying it by several hours. I did not ejaculate inside of her, however I am worried about the issue of pre-ejaculate containing sperm. What would the best course of action be to take to avoid pregnancy? (I know in the future to always use a condom) Should I purchase an emergency contraceptive? Or should we try to schedule an appointment for a copper iud?

Doctor: