Um... mine is pretty much the same as it was pre pregnancy. I didn't get stretch marks or loose skin with any of my 4. I have a little podge after DD3, but its not really noticable & I've just noticed its starting to disappear.

I'm no help, but I don't think anyone can really tell you what will happen to your body IYKWIM? My mum is similar to me, so maybe ask your mum about her experience (although, it could be different for her too!) Stretch marks are genetic