found some stuff on baby centre that we were talking about previously...
The dark color of the linea nigra will gradually fade over a year, but that too may not completely disappear.
How long will it take for my belly to shrink back to normal?
For most women it takes months to get rid of the "pregnancy pouch" — and sometimes it never goes away.
Patience is key. It took nine months for your abdomen to stretch to accommodate a full-term baby, so it makes sense that it would take that long or longer to tighten back up.
The speed and degree of this transition depends largely on your normal body size, how much weight you gained during pregnancy, how active you are, and your genes. Women who gained less than 30 pounds and exercised regularly during pregnancy, who breastfeed, and who have had only one child are more likely to slim down quickly.
Some baby bulges require more effort. A low-calorie diet can help you lose weight, but give nature and exercise time to work first. Wait at least six weeks (preferably several months, especially if you're nursing) before cutting back on calories. Dieting too soon after giving birth may reduce your milk supply and can make you feel more fatigued.
And don't go on a strict diet — women need a minimum of 1,200 calories a day to stay healthy, and most women need much more than that — between 1,800 and 2,200 calories a day — to keep up their energy and mood.
More from here:
http://www.babycenter.com/0_your-post-baby-belly-why-its-changed-and-how-to-tone-it_1152349.bc?showAll=true