While there are lots of exercise programs that could help, you are only a month postpartum- has your lochia even stopped yet? When it does you can do crunches or pilates core work, but for the first few months, I just try to concentrate on holding my belly in. It makes a big difference, you tend to let go in that last month of pregnancy and holding it in helps strengthen the muscles gradually. I figure if it took me 9 months to grow the belly, I should give myself at least that much time to get back into my jeans.
Here's a quote from a friend that I really like:
"I think of my body now (the slightly different hip
shape, different breast shape/size/softness) in
biological terms of maturity. The female body doesn't
finish maturing in adolescence - it takes bearing a
child & nursing that child to actually take the body
through all of the growth to adulthood. For example
the breasts go through a 'finishing' process of growth
during the 1st pregnancy that completes the start of
breast development begun in the teens. Womyn who lose
a 1st pregnancy and never carry another one are at a
higher risk for breastcancer - that 'finishing'
development of the breasts got arrested & didn't get
done, leaving growth potential to go awry.
None of us may have the body we had at 15 ever again -
not because we're not in shape/dieting etc - but
because our bodies weren't DONE at 15, or 20 or
whenever pre-childbearing.
Knowing this stuff allows me to look at my body as
doing/being just how it should be, rather than 'not
ever getting back to my REAL body'"
-earthmoon