Pregnancy underwear have come a long way in a short amount of time. My mom and Aunt tell me horror stories of maternity underwear that were Granny Panties the size of the State of Texas. I don't know about you, but being pregnant made me feel large enough without adding some massive underwear to the equation.
I highly suggest going to Motherhood Maternity and purchasing some good pregnancy underwear. They make a world of difference in your comfort, and are great to wear after you've had your baby and are recovering. Just click on the image to the left to head over to their website.