Most emergency contraceptives (Plan B, apparently this Cryselle, etc.) require use within 72 hours of the unprotected sex and state that the sooner you take it, the better it is. I would suggest talking to your parents (or at least your mom). As much as it's going to suck and as scary as it's going to be to tell a parent, you would much rather it be now being responsible trying to avoid pregnancy than a few weeks from now when you potentially miss a period and are pregnant.
I would also recommend you always use a condom from here on out and check for breaks to be sure you don't face this scary, emotionally overwhelming situation again. Emergency contraceptives are not good to take very often as they are such a high dose of hormones and can mess with your cycle.
Looking further into it, Cryselle isn't an emergency contraceptive but rather a normal daily use birth control pill and therefore would not prevent pregnancy in an emergency situation (at least not in the fashion you read to use it). Plan B and Next Choice are the most common emergency contraceptives.