I'm tall, athletic and weigh around 175 lbs. will plan b really not work for me?

Should: Your height, weight and activity level should not impact the effectiveness of PlanB. A better plan (no pun intended) might be to use precautions to obviate the need for that medication.

Plan B: Plan B should work as well for you as any other woman. Plan B One-Step is up to 89 % effective when taken within 72 hours (3 days) after unprotected sex. It can reduce chance of pregnancy by up to 95% if used within 24 hours. It continues to reduce the risk of pregnancy up to 120 hours (5 days) after unprotected sex, but is less effective as time passes.