EDIT: I just realized this is very similar (although not as nice looking) as one done on Bella Crochet. You can find her pattern here. (and I am quite sure her pattern is easier to follow!
Turning a simple granny square into a heart
The first picture is done in Aunt Lydia’s #10 crochet thread, the 2nd is done in a worsted weight yarn.
- Into a magic ring, ch 3 [for 1st dc], 2 dc, ch 2, 3 dc, ch2, 3dc, ch 2, 3 dc, ch 2, join to beg ch 3, turn [3 dc per side, 2 ch between each set]
- Into the 1st ch 2 sp: ch 3 [for 1st dc], dc, (dc in each of next 3 dc, in ch 2 sp: 2 dc, ch 2, 2 dc) X 3, dc in last 3 dc, 2 dc in 1st ch 2 sp, ch 2, join to beg ch 3 [5 dc per side, 2 ch between each set]
- [Working on one side only]: SS to 2nd dc, [ch 1, dc] X 5 into the 4th dc of side, ch 1, ss into 6th dc of side, ss into ch 2 sp of same side, turn [5 dc, 10 ch 1 spaces]
- [Still working on same side] (ch 1, dc, ch 1, dc, ch 1) into each of next 5 ch 1 spaces, ss into ch 2 sp of round 2 [10 dc, 15 ch 1 spaces]
- [Working on next side]: repeat round 3 and 4, turn after final ss.
- sc in each stitch and chain around 1 side of heart, in bottom corner sc, ch 2, sc, sc in each stitch and chain around 2nd side of heart.
- Add embellishment to center