Do your cardio in the AM BEFORE breakfast.
Yes, it will not feel the greatest in the beginning, but you'll get used to it.
All night your body is in a fast, beginning when you stop eating after 8 pm..all night long your body is using stored body fat for energy (yes, there is energy spent while sleeping). When you put cardio on top of that before your first meal, it just torches fat. And on top of all that, your metabolism will be humming for the rest of the day. Your cardio can consist of whatever you want. I preferably like to do my CardioX or KenpoX cd since I'm doing P90X..but it can also consist of a jog. The point is to get moving before that first meal. Try it for a week, 3 of those mornings being cardio. You can still do your strength training later in the day. I gaurauntee that more "poundage" will be shed.
It all goes back to how much you want to invest in your body and health. Diligence and hard work are the only thing that's going to get you back into your pre-pregnancy jeans, that hot bikini, or whatever you have in mind. Keep your eyes on the prize.