A 22-year-old woman presents to her GP requesting emergency contraception. She had unprotected sexual intercourse (UPSI) 60 hours ago. Her last menstrual period (LMP) was 12 days ago, and her cycles are regular (28 days). She has no contraindications to any method. According to Faculty of Sexual and Reproductive Healthcare (FSRH) guidelines, which is the most effective method of emergency contraception to offer her at this time?