There are two main types of emergency contraceptive pills available. Levonorgestrel (like Plan B One-Step): Available over the counter without a prescription. It works best when taken within 72 hours (3 days) of unprotected sex. Ulipristal acetate (like Ella): Requires a prescription but is more effective, especially if you are close to ovulation or have a higher BMI. It works up to 120 hours (5 days) after unprotected sex. Both are most effective the sooner you take them. Please consult a pharmacist or healthcare provider immediately to help you choose the best option for your timeline and body.