Wow, thanks so much! So many replies so quickly :) I love this place.
Carolaug, those are 6" blocks. I'm using the Mixtape Quilt pattern from Oh Fransson in the "Favorite Songs" variation. I saw a FQ bundle of Amy Butler fabrics and just had to make something with it.
I love the idea of a deep pink or variegated thread for quilting, as well as putting some hearts into the quilting! I never would have thought of either idea.
I am hoping it's just a needle issue causing the weird stitches, since I'm switching to a machine quilting needle for the quilting anyways. I've rethreaded the machine a couple times and it doesn't seem to have helped.