If you are 17 or older, you can buy emergency contraception at a pharmacy without a prescription.
As of April, 2009, anyone over the age of 17 can get emergency contraception (also called "Plan B") without a prescription. To make it easy to buy Plan B, pharmacies are supposed to put them in a place in a pharmacy where they are easy to pick-up and buy. This is why Plan B is now called an "over-the-counter" medicine.
It may take awhile for the pharmacies to make the emergency contraceptive pills "over-the counter." Until then, it is still pretty easy to get them. You can go to a clinic or get a prescription from your doctor. You can even get emergency contraceptive pills free at many clinics.