Make more than a baby.
DIY a full-body, contoured maternity pillow.
It may be big, but it'll work wonders on your aching back and help you get some sleep. Find the tutorial (and PDF pattern) here.
You can also make your own regular-sized maternity pillow.
Learn how here.
Sew a two-seam maternity dress.
This chic number is very easy to make. Learn how here.