10 Lbs in 3 weeks?

Is this something I can do? I would really like to challenge myself and try and lose 10 Lbs in 3 weeks or less. I'm thinking, it is doable, If I stick to my diet. Any thoughts?
August 27th (which also happens to be my birthday), we're going on vacation. That requires a swimming suit! In public! (when we went swimming with my boys last week, it was just us in the pool)!! Haven't done that because of how self conscious I am about my body and being in a swim suit. So, i'm thinking 10 Lbs in 3 weeks (the trip is at least 6 weeks away) should make me feel VERY good about myself! :)