Etsy has a lot of great shops. Do you like a certain style? Like pearls, hearts, simple, lots of bling? A simple search turned out to be the way to go for me! Trust me, when you see it, you'll know! There are also a lot of online stores if you google "jewelry" and the phrase/word that describes what you are envisioning...
Don't worry, you have plenty of time! I'll have to wait until I get my dress (early May) to even begin to think about buying something! Luckily I'll only be wearing some killer earrings, so I hope that will narrow the search