I got mine at motherhood as well. When I bought them a few weeks ago there was a buy two get one free sale.
I got mine at target they are about $16.99 & up but if you have a baby registry you can add them & when they send you 15% off cards one for yourself & like 4 more for friends you can use them.
I have to go to the Calvin Klein Outlet to find my size. I am usually a dd now being 29 weeK's i am a H it's crazy......
Motherhood is great they will measure you and they have tons of sizes
Target has some.EBay has some.
Motherhood Maternity has good sales on there nursing bras, if you have one close by you.