I had unproteted sex this morning, as the condom split, and I went to get emergency contraception literally straight away (within 30mins of the sex, I had taken the tablet). However, I have an appointment to get the contraceptive implant on Wednesday but I need to prove that I'm not pregnant. My question is, how long does it take the emergency contraception pill take to take effect so that I can take a pregnancy test to ensure it has worked?