first off, let me just say tha tI love the pattern you picked for this quilt. It is going to look great! That being said, I would also guess that your seam is just a tad too big. That combined with pressing can eat up just that little bit you need. Double check your seams like the other ladies said and hopefully all the blocks aren't sewed so you don't have to unsew or cut them all down. That is what I'm having to do right now. :0(