I feel like ive lost a lot of weight since having my son, I don't have much of an appetite and my…

I feel like ive lost a lot of weight since having my son, I don't have much of an appetite and my stomach looks a lot smaller then what it was before I was pregnant . is it normal for that to happen ? I only eat at dinner time and even then I get so full I don't finish my food and then afterwards I have to go to the bathroom !