You can find this very easy pattern on page 87 on the book by Kim Werker titled Get Hooked Simple Steps to Crochet Cool Stuff.

Variation: To finish heart border, after last stitch, do not fasten off, join a different color yarn, continue around doing slip stitches until you reach the first stitch of hearts curve, join with a slip stitch then: ch 1, (sc in next st, ch1) Repeat what is in parentheses and go around the heart. To Keep the center of the heart low do a slip stitch (do not chain one after this slip stitch and continue doing (sc, ch1) around. Use the needle to weave in any tail.

To enhance the hearts shape, I recommend blocking the heart.