Where, oh where did my big butt go?

I am 32 years old, and I have struggled my whole life with my weight and body image. It took me nearly 30 years to actually accept certain things about myself. Specifically, I have always had a big butt--a black guy I used to work with said I had "junk in the trunk." The popularity of J Lo and Beyonce (both of whom have ample booties) helped me embrace this attribute. So you can imagine my horror when I looked in the mirror just days after giving birth to the cutest baby in the world only to discover that my butt had disappeared! Now I expected certain body parts to droop and sag after having a baby. However, my butt was not one of those body parts. I mean, it is gone--just a flat saggy mess. How is this fair? My behind had nothing to do with bearing this child (okay maybe a little), but it is suffering along with my boobs and belly. Looks like the Stairmaster is in my future.