How to lose my stomach while feeding?

I have a 3 1/2 year old, a 2 year old and a 4 month old. I am feeding my 4 month old so i can not take anything. What are some ways that I can lose my baby stomach while feeding. I am watching what I eat and dont have any exercise equiptment and its still chilly so we cant go outside all the time yet. Can you give me ideas of what kinds of exercises I can do without equiptment.