Buy a new pack-- you can use that pack as a back up incase you lose pills or something, but that pack is done.
You can wait for your next cycle to start a new pack, but you'll need to use a back up method like condoms until you're a week into your pills.
OR you can start the pack as soon as you get it, but your cycle will be off.
Since its likely your cycle will be off anyways, you may as well just start the pack when you get it and just rememeber that you won't get your bleeding as normal for another 3 months (you'll be having that as a side effect to EC anyways).
Did you double check the amount of your kind of pill to take as EC or did you just take them?