Maddie is 22 years old and attends the GP seeking emergency contraception after an episode of unprotected sexual intercourse (UPSI) 6 hours ago. She has a regular 28 day cycle and the first day of her last menstrual period was 10 days ago. She used Levonorgestrel 1.5mg once last year and is keen to have this prescribed again. She does not want the copper coil. In addition, she enquires about quick starting the combined hormonal contraceptive pill. Her BMI is 24 kg/m2.
After a lengthy discussion you agree to prescribe Levonorgestrel and the combined hormonal contraceptive pill (Marvelon). For how long after starting the contraceptive pill should she take extra precautionary measures?