Hi, In pregnancy
abdominal muscles get weak due to overstreching.to get rid of tummy after delivary,this muscle tone
is to be brought back. it's 1 mth. past delivary please restart your routine.
have a walk with medium speed daily for30 mts &gradually increase it to45 mts brisk walk.
start exersises like sit ups ,Yogasanas ,Kapalbhati pranayam.
Eat vitamin,calsium &protein diet
Continue breast feeding
In couple of mths you will get what you desire.