Which is the best form of exercise to lose stomach fat?

I am overall a thin person, but I do however have some stomach fat. Which is the best form of exercise in order to lose it? I have a large gym in my house where I shall do my exercise. Keeping in mind that I do not exercise much at all.

Might I also add that I of course shall not be exercising now as I am 8 and a half months pregnant, but I shall be after I give birth.