Avery offers heart-shaped labels in our Blank Labels line. These are available for purchase at https://www.avery.com/blank/labels/94603. They are a bit smaller than 3" x 2" and you can print to the edge of the labels. You can choose from a variety of colors and material types and order in any sheet quantity you'd like.
You can design these using the Presta 94603 template in Avery Design & Print Online.
You can also download a Presta 94603 template for Word, Photoshop or Illustrator.
Here's some information on recommended printer settings.
If you want Avery to print heart labels for you, Avery WePrint offers 1.5" x 1.5" heart labels.